diff --git a/lib/graph/apply-proposal.js b/lib/graph/apply-proposal.js
index 1d0a233..c92ca83 100644
--- a/lib/graph/apply-proposal.js
+++ b/lib/graph/apply-proposal.js
@@ -87,6 +87,45 @@ function validateAddedUnknowns(graph, proposal) {
       .filter((node) => node.kind !== "unknown")
       .map((node) => node.id),
   ]);
+  const proposalNodeById = buildNodeById(graph, proposal.addedNodes);
+
+  function hasExplicitNodeReference(fromNode, toNodeId) {
+    if (!fromNode || !toNodeId) return false;
+
+    return (
+      fromNode.parentId === toNodeId ||
+      fromNode.dependsOn.includes(toNodeId) ||
+      fromNode.affects.includes(toNodeId) ||
+      fromNode.childIds.includes(toNodeId)
+    );
+  }
+
+  function hasExplicitAnswerDerivedRelationship(unknownNode) {
+    const connectedEdge = proposal.addedEdges.find(
+      (edge) =>
+        (edge.fromNodeId === unknownNode.id &&
+          answerDerivedNodeIds.has(edge.toNodeId)) ||
+        (edge.toNodeId === unknownNode.id &&
+          answerDerivedNodeIds.has(edge.fromNodeId)),
+    );
+
+    if (connectedEdge) {
+      return true;
+    }
+
+    for (const answerDerivedNodeId of answerDerivedNodeIds) {
+      const answerDerivedNode = proposalNodeById.get(answerDerivedNodeId);
+
+      if (
+        hasExplicitNodeReference(unknownNode, answerDerivedNodeId) ||
+        hasExplicitNodeReference(answerDerivedNode, unknownNode.id)
+      ) {
+        return true;
+      }
+    }
+
+    return false;
+  }
 
   for (const unknownNode of addedUnknowns) {
     const meaningKeys = [
@@ -128,15 +167,7 @@ function validateAddedUnknowns(graph, proposal) {
       );
     }
 
-    const connectedEdge = proposal.addedEdges.find(
-      (edge) =>
-        (edge.fromNodeId === unknownNode.id &&
-          answerDerivedNodeIds.has(edge.toNodeId)) ||
-        (edge.toNodeId === unknownNode.id &&
-          answerDerivedNodeIds.has(edge.fromNodeId)),
-    );
-
-    if (!connectedEdge) {
+    if (!hasExplicitAnswerDerivedRelationship(unknownNode)) {
       errors.push(
         `New unknown must be explicitly related to an answer-derived node: "${unknownNode.id}"`,
       );
diff --git a/scripts/reproduce-commercial-value-update.mjs b/scripts/reproduce-commercial-value-update.mjs
new file mode 100644
index 0000000..d789f05
--- /dev/null
+++ b/scripts/reproduce-commercial-value-update.mjs
@@ -0,0 +1,97 @@
+import { mkdir, writeFile } from "node:fs/promises";
+
+const BASE_URL =
+  process.env.CONFIDENCE_ENGINE_BASE_URL || "http://127.0.0.1:3000";
+const OUTPUT_DIR = "tests-results/commercial-value-update";
+
+const scenario = "I think therefore I am";
+const answer =
+  "Deciding whether to build the Confidence Engine due to uncertainty about its commercial value.";
+
+async function postJson(path, body) {
+  const response = await fetch(`${BASE_URL}${path}`, {
+    method: "POST",
+    headers: {
+      "content-type": "application/json",
+    },
+    body: JSON.stringify(body),
+  });
+
+  const json = await response.json();
+  return { status: response.status, json };
+}
+
+function printLine(label, value) {
+  const rendered = value === undefined ? null : value;
+  console.log(`${label}: ${JSON.stringify(rendered)}`);
+}
+
+async function main() {
+  await mkdir(OUTPUT_DIR, { recursive: true });
+
+  const startResult = await postJson("/api/cases/start", { scenario });
+  await writeFile(
+    `${OUTPUT_DIR}/start-response.json`,
+    JSON.stringify(startResult, null, 2),
+  );
+
+  const selectedQuestion = startResult.json?.selectedQuestion?.question || null;
+
+  let updateResult = {
+    status: null,
+    json: {
+      success: false,
+      stage: "request_construction",
+      errors: ["Missing selected question from start response"],
+    },
+  };
+
+  if (startResult.json?.success && selectedQuestion) {
+    updateResult = await postJson("/api/cases/update", {
+      situationGraph: startResult.json.situationGraph,
+      previousQuestion: selectedQuestion,
+      answer,
+    });
+  }
+
+  await writeFile(
+    `${OUTPUT_DIR}/update-response.json`,
+    JSON.stringify(updateResult, null, 2),
+  );
+
+  printLine("start success", startResult.json?.success ?? false);
+  printLine("update success", updateResult.json?.success ?? false);
+  printLine("update stage", updateResult.json?.stage ?? null);
+  printLine(
+    "proposal added nodes",
+    updateResult.json?.proposal?.addedNodes?.map((node) => node.id) ?? null,
+  );
+  printLine(
+    "proposal added edges",
+    updateResult.json?.proposal?.addedEdges?.map((edge) => ({
+      id: edge.id,
+      fromNodeId: edge.fromNodeId,
+      toNodeId: edge.toNodeId,
+      relationship: edge.relationship,
+    })) ?? null,
+  );
+  printLine(
+    "proposal resolved unknown IDs",
+    updateResult.json?.proposal?.resolvedUnknownNodeIds ??
+      updateResult.json?.resolvedUnknownNodeIds ??
+      null,
+  );
+  printLine(
+    "errors",
+    updateResult.json?.errors ??
+      updateResult.json?.proposalErrors ??
+      updateResult.json?.graphValidationErrors ??
+      updateResult.json?.validationErrors ??
+      null,
+  );
+}
+
+main().catch((error) => {
+  console.error(error instanceof Error ? error.message : String(error));
+  process.exitCode = 1;
+});
diff --git a/tests/graph/apply-proposal.test.js b/tests/graph/apply-proposal.test.js
index bc68e5f..f43fe1a 100644
--- a/tests/graph/apply-proposal.test.js
+++ b/tests/graph/apply-proposal.test.js
@@ -623,6 +623,208 @@ describe("applyValidatedProposal", () => {
     );
   });
 
+  it("accepts a newly added unknown explicitly linked through answer-derived node fields", () => {
+    const { graph, ids } = makeApplicationFixture();
+
+    const proposal = {
+      addedNodes: [
+        makeNode({
+          id: "n-answer-context",
+          label: "Build Confidence Engine decision",
+          description: "Decision context introduced by the answer.",
+          kind: "state",
+          status: "supported",
+          confidence: "medium",
+          childIds: ["n-commercial-value"],
+        }),
+        makeNode({
+          id: "n-commercial-value",
+          label: "Commercial value definition",
+          description:
+            "Need commercial value definition because the decision depends on it.",
+          kind: "unknown",
+          status: "unknown",
+          confidence: "high",
+          dependsOn: ["n-answer-context"],
+        }),
+      ],
+      updatedNodes: [
+        {
+          nodeId: ids.complaintRateUnknown,
+          previousStatus: "unknown",
+          newStatus: "resolved",
+          previousValue: null,
+          newValue: "Decision whether to build Confidence Engine",
+          reason: "The answer resolves the original context unknown.",
+        },
+      ],
+      addedEdges: [],
+      removedEdgeIds: [],
+      resolvedUnknownNodeIds: [ids.complaintRateUnknown],
+      affectedNodeIds: [],
+      selectedQuestion: {
+        nodeId: "n-commercial-value",
+        question: "How should commercial value be defined for this decision?",
+        reason: "A consequential unknown remains unresolved.",
+      },
+    };
+
+    const result = applyValidatedProposal({ situationGraph: graph, proposal });
+
+    expect(result.success).toBe(true);
+    expect(result.selectedQuestion?.nodeId).toBe("n-commercial-value");
+  });
+
+  it("rejects a newly added unknown linked only to the original unresolved node when that node is not answer-derived", () => {
+    const { graph, ids } = makeApplicationFixture();
+
+    const result = applyValidatedProposal({
+      situationGraph: graph,
+      proposal: {
+        addedNodes: [
+          makeNode({
+            id: "n-commercial-value",
+            label: "Commercial value definition",
+            description:
+              "Need commercial value definition because the decision depends on it.",
+            kind: "unknown",
+            status: "unknown",
+            confidence: "high",
+            dependsOn: [ids.complaintRateUnknown],
+          }),
+        ],
+        updatedNodes: [],
+        addedEdges: [
+          makeEdge({
+            id: "e-legacy-unknown-commercial-value",
+            fromNodeId: ids.complaintRateUnknown,
+            toNodeId: "n-commercial-value",
+            relationship: "depends_on",
+            confidence: "medium",
+            description: "Links only to the original unresolved unknown.",
+          }),
+        ],
+        removedEdgeIds: [],
+        resolvedUnknownNodeIds: [],
+        affectedNodeIds: [],
+        selectedQuestion: {
+          nodeId: "n-commercial-value",
+          question: "How should commercial value be defined for this decision?",
+          reason: "A consequential unknown remains unresolved.",
+        },
+      },
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.errors.join(" ")).toContain(
+      "explicitly related to an answer-derived node",
+    );
+  });
+
+  it("rejects a floating emergent unknown with no explicit relationship", () => {
+    const { graph } = makeApplicationFixture();
+
+    const result = applyValidatedProposal({
+      situationGraph: graph,
+      proposal: {
+        addedNodes: [
+          makeNode({
+            id: "n-floating",
+            label: "Floating unknown",
+            description: "Need this because it matters to the decision.",
+            kind: "unknown",
+            status: "unknown",
+            confidence: "medium",
+          }),
+        ],
+        updatedNodes: [],
+        addedEdges: [],
+        removedEdgeIds: [],
+        resolvedUnknownNodeIds: [],
+        affectedNodeIds: [],
+        selectedQuestion: {
+          nodeId: "n-floating",
+          question: "What would resolve Floating unknown?",
+          reason: "Test case for floating unknown rejection.",
+        },
+      },
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.errors.join(" ")).toContain(
+      "explicitly related to an answer-derived node",
+    );
+  });
+
+  it("accepts the reported live-shaped commercial-value proposal when the linkage is explicit in node references", () => {
+    const { graph, ids } = makeApplicationFixture();
+
+    const proposal = {
+      addedNodes: [
+        makeNode({
+          id: "answer_context_build",
+          label: "Build Confidence Engine decision context",
+          description:
+            "The answer introduces a concrete decision about whether to build Confidence Engine.",
+          kind: "state",
+          status: "known",
+          confidence: "high",
+          dependsOn: [ids.complaintRateUnknown, "nu_commercial_val"],
+          childIds: ["nu_commercial_val"],
+          affects: ["nu_commercial_val"],
+        }),
+        makeNode({
+          id: "nu_commercial_val",
+          label: "Commercial viability assessment of Confidence Engine",
+          description:
+            "The commercial viability of Confidence Engine remains unknown because resolving it is needed to decide whether building it is justified.",
+          kind: "unknown",
+          status: "unknown",
+          confidence: "medium",
+          dependsOn: ["answer_context_build"],
+          childIds: ["answer_context_build"],
+        }),
+      ],
+      updatedNodes: [
+        {
+          nodeId: ids.complaintRateUnknown,
+          previousStatus: "unknown",
+          newStatus: "resolved",
+          previousValue: null,
+          newValue:
+            "Deciding whether to build the Confidence Engine due to uncertainty about its commercial value.",
+          reason: "The answer resolves the original context unknown.",
+        },
+      ],
+      addedEdges: [],
+      removedEdgeIds: [],
+      resolvedUnknownNodeIds: [ids.complaintRateUnknown],
+      affectedNodeIds: [
+        ids.complaintRateUnknown,
+        "answer_context_build",
+        "nu_commercial_val",
+      ],
+      selectedQuestion: {
+        nodeId: "nu_commercial_val",
+        question:
+          "How should commercial viability be defined for this decision?",
+        reason: "A foundational commercial-value unknown remains unresolved.",
+      },
+    };
+
+    const result = applyValidatedProposal({ situationGraph: graph, proposal });
+
+    expect(result.success).toBe(true);
+    expect(result.updatedSituationGraph.resolvedNodeIds).toContain(
+      ids.complaintRateUnknown,
+    );
+    expect(
+      result.updatedSituationGraph.nodes.some(
+        (node) => node.id === "nu_commercial_val",
+      ),
+    ).toBe(true);
+  });
+
   it("rejects selected question referencing resolved node", () => {
     const { graph, proposal, ids } = makeApplicationFixture();
 
diff --git a/tests/ui/scenario-form.test.jsx b/tests/ui/scenario-form.test.jsx
index f0f39fe..0a29573 100644
--- a/tests/ui/scenario-form.test.jsx
+++ b/tests/ui/scenario-form.test.jsx
@@ -438,6 +438,26 @@ describe("graph-backed UI rendering", () => {
     expect(html).toContain("Commercial value definition");
   });
 
+  it("successful update renders prior and new state together", () => {
+    const html = renderToStaticMarkup(
+      <GraphUpdateView
+        updateResult={{
+          ...makeUpdateSuccess(),
+          previousSituationGraph: makeGraphResult().situationGraph,
+        }}
+      />,
+    );
+
+    expect(html).toContain("Previous active unknown");
+    expect(html).toContain("Resolved unknowns");
+    expect(html).toContain("Newly surfaced unknowns");
+    expect(html).toContain("New active unknown");
+    expect(html).toContain("Next question");
+    expect(html).toContain(
+      "How should commercial value be defined for this decision?",
+    );
+  });
+
   it("situation graph marks newly surfaced and active unknowns", () => {
     const html = renderToStaticMarkup(
       <SituationGraphView
@@ -514,6 +534,30 @@ describe("graph-backed UI rendering", () => {
     expect(html).toContain("bad proposal");
   });
 
+  it("failed update does not fabricate history", () => {
+    const html = renderToStaticMarkup(
+      <>
+        <UpdateErrorPanel
+          updateError={{
+            error: "Update case failed",
+            errors: [
+              'New unknown must be explicitly related to an answer-derived node: "nu_commercial_val"',
+            ],
+          }}
+        />
+        <GraphUpdateView updateResult={null} />
+      </>,
+    );
+
+    expect(html).toContain("Update error: Update case failed");
+    expect(html).toContain("nu_commercial_val");
+    expect(html).not.toContain("Previous active unknown");
+    expect(html).not.toContain("Resolved unknowns");
+    expect(html).not.toContain("Newly surfaced unknowns");
+    expect(html).not.toContain("New active unknown");
+    expect(html).not.toContain("Proposal details");
+  });
+
   it("proposal details remain collapsible", () => {
     const html = renderToStaticMarkup(
       <GraphUpdateView updateResult={makeUpdateSuccess()} />,