The RAF's Nimrod Safety Case was found by the 2009 Haddon-Cave Review to be a 'tick-box' compliance exercise, riddled with errors, ahead of a crash that killed 14 crew

An RAF Nimrod MR2 (XV230) exploded in mid-air over Afghanistan in 2006, killing all 14 crew aboard. The subsequent Haddon-Cave Review (2009) examined the Nimrod's safety case — the formal, structured argument that the aircraft was safe to fly — and found it "a lamentable job from start to finish... riddled with errors," per Aerossurance's summary of the primary Review. The process of drawing it up "became essentially a paperwork and 'tick-box' exercise," faulted for "Compliance only (drawn up to give the answer desired, i.e. that the platform is safe)."

This is the documented failure mode of the same argumentation apparatus — the safety case — now being proposed for frontier-AI assurance. The apparatus did not fail because the notation was wrong; it failed because the incentive behind the paperwork was to confirm a predetermined conclusion ("the platform is safe") rather than to genuinely test it for gaps.