So I just played a guy. I played a pretty clean game and finished it with just 1 trade. But at the end the guy made a move that allowed me to mate in 1. But it's not a blunder? Just a mistake? It seemed like a borderline psychotic error to me when he played it. Was my position just too strong at that point and it was already mate in 3 or something if he played with stockfish tier accuracy? I'm relatively new so I don't know how to evaluate the strength of my position and I'm not letting chesscom jew me out of money.