[Bug] Fallback model triggered unexpectedly during legacy codebase reverse engineering task

Bug Description
I've had a fallback model message while executing a reverse engineering in a legacy codebase to extract business rules and rewrite it. The codebase is of my own, which I think it shouldn't.
"Sessão 22 — ClienteController, os entry points (D-02). Ordem: Passo 0, localizar o gerador de manifesto (l01_manifesto.py), gerar o manifesto da unidade (está acima do gatilho de fatiamento) e ler o cabeçalho da classe (atributos, DI, helpers) antes da primeira sub-sessão. Made 6 scratchpad edits +810, read 1 file, ran 8 shell commands Loaded G2Solution\G2.Web.Titan\CLAUDE.md ● Fable 5's safeguards flagged this message. Our intentionally broad safeguards allow us to deliver more capabilities faster, but can sometimes flag legitimate coding, cybersecurity, and biology tasks. Switched to Opus 4.8. Send feedback with /feedback or learn more ⎿ Tip: You can configure model switch behavior in /config"

Environment Info

• Platform: win32
• Terminal: windows-terminal
• Version: 2.1.227
• Feedback ID: 6379b506-c1bb-4295-b641-0380d1ca52d8

Errors

[{"error":"TelemetrySafeError: VirtualMessageList: itemKeys/messages length desync (keys=36 messages=35 range=[0,36))\n    at jjE (B:/~BUN/root/src/entrypoints/cli.js:23325:8179)\n    at Bkm (B:/~BUN/root/src/entrypoints/cli.js:23325:1103)\n    at ti (B:/~BUN/root/src/entrypoints/cli.js:2577:21360)\n    at Au (B:/~BUN/root/src/entrypoints/cli.js:2577:40453)\n    at Q6 (B:/~BUN/root/src/entrypoints/cli.js:2577:51374)\n    at Dye (B:/~BUN/root/src/entrypoints/cli.js:2577:89044)\n    at Pye (B:/~BUN/root/src/entrypoints/cli.js:2577:87995)\n    at Eue (B:/~BUN/root/src/entrypoints/cli.js:2577:87814)\n    at fv (B:/~BUN/root/src/entrypoints/cli.js:2577:84079)\n    at bt (B:/~BUN/root/src/entrypoints/cli.js:2577:6660)","timestamp":"2026-08-11T12:28:27.748Z"}]