What happened
Fable 5 backlash after return: lower benchmark scores, frequent refusals, and automatic fallback to Opus 4.8.
Why it matters
For builders, the useful signal is not the drama itself but the operational lesson: users can experience a model as much through safety gating and routing behavior as through raw capability. The post also highlights how benchmark results and billing can diverge from user expectations when a system silently falls back to another model.
Severity rationale
[S2] widespread false refusals and silent model switching
Source: qbitai.com
See also: Hallucination Incident Index