I have been in that position, the person when asked will usually just reinforce their position with a statement like "It was there, I swear it was.", fault thei

I have been in that position, the person when asked will usually just reinforce their position with a statement like "It was there, I swear it was.", fault their recording technique, or their equipment. Believing your mind is playing tricks on you is really the last ditch effort at rationalizing something for most people. They don't come to that conclusion easily without some sort of history or practice doing so.