Kraevac

I have a player who has twice now been banned from my server for using Godmode. This player is not an admin or mod or anything like that. My question is, are their any known hacks that a player can use to enter GM and/or can there be false positives. I have never had issues with this player in the past, but twice in the last 12 hours he has been kicked and banned for using GM. I trust this player, but at the same time, if there is something out there that he could be using......well just can't have that.