Architecture & practice·Judgement and reasoning traps
you believed it was the cache and read the logs looking for the cache, and found something.
Confirmation bias
Seeking and weighting evidence that supports the hypothesis you already hold. It is at its most costly during debugging and incidents, where a plausible early theory determines which logs get read and which get skipped. The practical defence is to state what would disprove the theory before looking, and to hand the theory to someone who has not spent an hour in it.