Here is a more recent incident. I was playing 15 minute chess and after the game my opponent accused me of cheating by using a chess engine/
He decided to make me his enemy. He was a strong player and we broke about even.
The very last game we played it was a gambit but I defended well and we got to an end game when he had 3 pawns but his king was in the corner and he was one move away from being check mated. However It was a tough game and I was nervous and my hand slipped and I had to start my check mate move again. I started to move my queen--But I lost on time.
He won! This was the position:
I was playing in the 1973 U S Open. My opponent was the former Illinois Champion and USCF master, Dr. Steve Tennant.
He and I had played before in city vs city teams and I had gotten somewhat the better of it.
This was my 8th game in that US Open and I was dead tired from working during the day and traveling to Chicago and then back to Kankakee.
I played the white side of the Smith Morra Gambit and quickly got an advantage. We later were in a rook and pawn end game where I was up two pawns. But I was so tired that my head was swimming and I could not think.
Soon the game ended in a draw. And I will never forget what my friend, Steve, said: "You were up two pawns and couldnt win! You were up two pawns and couldn't win!"
He kept repeating this.