Opponent moves after being checkmated????

Hi guys, I had the weirdest experience. I checkmated my opponent and he just moved a pawn up. I was just waiting for my win to show up and my time ran out and I lost. It was game number 103173148. I was wondering if I overlooked something or that anyone else had this experience?

Thanks,

Albert.

I commented on the game I think you were referring to. The game number didn't seem to show up on my end, so I am not certain I commented on the game you are talking about. 

EDIT: I commented on the correct game. Thank you AndTheLittleOneSaid.

http://www.chess.com/livechess/game.html?id=103173148

 That game's not checkmated. The queen needed to go to c7.

Correct.

20 Qa8#

 That's indeed true.

Do you think that was what he may have been thinking? And by the time he made his move he accidentally made a different move. Or just pointing it out?

Sorry guys, I was away for a while. No, I actually made the move Qe7, which showed on the diagram but then the clock kept ticking for me so somehow the move apparently didn't register...

Sorry guys, I was away for a while. No, I actually made the move Qc7, which showed on the diagram but then the clock kept ticking for me so somehow the move apparently didn't register...

Posted it again with Qc7 instead of Qe7...

Was that before or after f5?

Because if it was before then you could not mate your opponent since your where in  check.

If it was after, then maybe you ran out of time before you could even move.

You are right... DARN COMPUTERS!!!!