could someone explain something?

i was playing a blitz game with a time frame of 1minute  3.several times in the course of the game my opponent's clock ran out yet he was able to continue playing. the first time my clock expired the game was over and my opponent won on time.

what am i missing?

thanks

xbg

There was lag, something which is impossible to fix completely. The system realised that your opponent made a move, but it took it a bit to recognise what the move was.

a belated thank you.