Did you have pre-move on?
Hacking and cheating

It's not en passant I was waiting to move suddenly the clock turned on him I was shocked. It was my time to move

Um, that's what's supposed to happen, isn't it? You're waiting to make your move and then it's your turn to move. Do you mean that your time dropped by a lot when it became your turn to move? That would indicate a connection or lag problem with your network connection - your opponent has actually made his move much earlier, but you don't see it on your end until their move does come through and your clock adjusts for the actual amount of time you had to play the move.
Your opponent can't affect your game at all, because you're not sending anything directly to each other's computers - you both send your moves to the Chess.com servers. If your opponent had the ability to hack the Chess.com server, they'd be doing a lot more than just stealing time from your clock.

It's not en passant I was waiting to move suddenly the clock turned on him I was shocked. It was my time to move
Accidental move is most likely.

Chess.com had a cheating problem, approximately 80% of all random matches use chess aids. The problem with chess.com is if cheaters are banned, then chess.com will lose over 80% of it members.
Lol 80 %, btw i got 90 % accurracy once in my games it does happen. That a average- bad player play's above his level. You can recognize a cheater with non stop 99 % accurracy games, and sometimes a very best move is obvious to find
Yes post the game so we can see what you mean. If David is correct with en passant it's legal
https://support.chess.com/article/683-what-is-en-passant