diff --git a/apps/web/src/lib/__tests__/gate-transition.test.ts b/apps/web/src/lib/__tests__/gate-transition.test.ts
index 40cb1d1c6..27ced91a9 100644
--- a/apps/web/src/lib/__tests__/gate-transition.test.ts
+++ b/apps/web/src/lib/__tests__/gate-transition.test.ts
@@ -112,6 +112,13 @@ describe('G.A.T.E. transition contract', () => {
     const assessed = assessZeroSim({ evidenceRefs: [] });
     expect(assessed.verdict).toBe('unverified');
     expect(assessed.reason_code).toBe('ZERO_SIM_MISSING_EVIDENCE');
+
+    const forcedReal = assessZeroSim({
+      result: { verdict: 'real', reason_code: 'ZERO_SIM_REAL' },
+      evidenceRefs: [],
+    });
+    expect(forcedReal.verdict).toBe('unverified');
+    expect(forcedReal.reason_code).toBe('ZERO_SIM_MISSING_EVIDENCE');
   });
 
   it('emits a versioned receipt whose hash matches canonical JSON without the hash field', () => {
diff --git a/apps/web/src/lib/gate-transition.ts b/apps/web/src/lib/gate-transition.ts
index 3b53d6237..dc6dd5117 100644
--- a/apps/web/src/lib/gate-transition.ts
+++ b/apps/web/src/lib/gate-transition.ts
@@ -217,10 +217,39 @@ export function assessZeroSim(input: {
   result?: ZeroSimResult;
   evidenceRefs?: GateEvidenceRef[];
 }): ZeroSimResult {
+  const refs = input.evidenceRefs ?? [];
   if (input.result) {
-    return input.result;
+    const candidate = input.result;
+    if (candidate.verdict === 'unreal') {
+      return candidate;
+    }
+    if (candidate.verdict === 'real') {
+      if (refs.length === 0) {
+        return { verdict: 'unverified', reason_code: 'ZERO_SIM_MISSING_EVIDENCE' };
+      }
+      for (const ref of refs) {
+        if (ref.hash && !SHA256_HEX.test(ref.hash)) {
+          return { verdict: 'unreal', reason_code: 'ZERO_SIM_UNREAL' };
+        }
+        if (ref.kind === 'live_url' && presentedLiveValue(ref) && !liveRefValue(ref)) {
+          return { verdict: 'unreal', reason_code: 'ZERO_SIM_UNREAL' };
+        }
+      }
+      return candidate;
+    }
+    if (refs.length === 0) {
+      return { verdict: 'unverified', reason_code: 'ZERO_SIM_MISSING_EVIDENCE' };
+    }
+    for (const ref of refs) {
+      if (ref.hash && !SHA256_HEX.test(ref.hash)) {
+        return { verdict: 'unreal', reason_code: 'ZERO_SIM_UNREAL' };
+      }
+      if (ref.kind === 'live_url' && presentedLiveValue(ref) && !liveRefValue(ref)) {
+        return { verdict: 'unreal', reason_code: 'ZERO_SIM_UNREAL' };
+      }
+    }
+    return { verdict: 'unverified', reason_code: 'ZERO_SIM_UNVERIFIED' };
   }
-  const refs = input.evidenceRefs ?? [];
   if (refs.length === 0) {
     return { verdict: 'unverified', reason_code: 'ZERO_SIM_MISSING_EVIDENCE' };
   }
@@ -268,10 +297,11 @@ function finish(
 }
 
 export function evaluateTransition(request: GateTransitionRequest): GateEvaluation {
-  const transitionId = request.transitionId.trim();
-  const kind = request.kind.trim();
-  const fromState = request.fromState.trim();
-  const toState = request.toState.trim();
+  const transitionId = (request.transitionId ?? '').trim();
+  const kind = (request.kind ?? '').trim();
+  const fromState = (request.fromState ?? '').trim();
+  const toState = (request.toState ?? '').trim();
+  const actor = request.authority?.actor ?? '';
   if (!transitionId || !kind || !fromState || !toState) {
     return finish(
       request,
@@ -282,12 +312,12 @@ export function evaluateTransition(request: GateTransitionRequest): GateEvaluati
     );
   }
 
-  if (!KNOWN_AUTHORITY_ACTORS.has(request.authority.actor)) {
+  if (!actor || !KNOWN_AUTHORITY_ACTORS.has(actor)) {
     return finish(
       request,
       'ESCALATE',
       'GATE_ESCALATE_AUTHORITY_UNKNOWN',
-      `Authority actor "${request.authority.actor}" is not a known G.A.T.E. actor.`,
+      `Authority actor "${actor || 'unknown'}" is not a known G.A.T.E. actor.`,
       request.zeroSim ?? { verdict: 'unverified', reason_code: 'ZERO_SIM_UNVERIFIED' },
     );
   }