I agree, his games should be removed entirely but Chess.com has never seen it that way.
"Cheaters"

How can one prove what specific games he cheated in? If he was cheating when removed (mid-tournament), he probably cheated in those games. The NCAA forfeits all games if a team has used an ineligible player.

Surely it doesn't really matter if he was cheating against some players and not against others in the tournament, since that is unfair to some players anyway, and the whole issue is on how to make it fairer? Any cheat should just have all his games forfeited and classed as losses, past or present.
Why cheat in the first place? If you are cheating to win you would do it with all of the games and your rating would show.

Cant you remove him from the tournament?
And if you can, will it remove his games too? I don't know....

This is the relevant FAQ article:
http://support.chess.com/Knowledgebase/Article/View/124/0/cheaters--cheating-what-you-need-to-know

How can one prove what specific games he cheated in? If he was cheating when removed (mid-tournament), he probably cheated in those games. The NCAA forfeits all games if a team has used an ineligible player.
You know wierd things happen @Chess.com, I was on live chess once and my opponent had terrible lag problems. To my surprise I was prompted without any reason by the administrator that I cannot chat more than 15 minutes?? I was warned that on the next instance my account would be closed. That scared the living daylights outta me so I resigned the game and logged out.
I would surmise the guy got banned in much the same circumstances not unless he informed the administrator he was quitting in the middle of the tournament and was punished for it. We really don't know maybe when we get to CHESS heaven we will find out.

I thought that nobody is cheating on chess.com.
http://www.chess.com/forum/view/community/chesscom---list-of-caught-cheaters
I am hosting a small tournament and one of the players was removed after his account was closed for cheating. The problem is that he completed three games before that. Those who lost to him have losses. Those who had not finished a game with him have victories. (He had no losses.) This alters the outcome of the tournament. Should not all of his games in any ongoing tournaments be forfeited to restore the integrity of the standings?