Here is a good resource that describes what the site does about cheating: https://www.chess.com/forum/view/community/discussions-about-cheating
Discussions in the open forums about cheating are not allowed but the reference I provided does describe an official club that does allow discussion.
his chess.com user is [Deleted].
some games he has has like 10 accuracy and some games he has 99.6 accuracy. not normal for 1000's player.
and its not only 1 time, he has really high accuracy in a lot of games. i mean 92+ accuracy in games,
can you check out his account and see if he is cheating? i think he is.
anyways if you think he is cheating then please report him.