Hoonter of Hoonters

How do I go about reporting them? I have proof. 1. Location he was glitched under. https://steamcommunity.com/sharedfiles/filedetails/?id=2398113469 2. Killed by him as he popped out the ground. https://steamcommunity.com/sharedfiles/filedetails/?id=2398112845 3. He's not denying it here. https://steamcommunity.com/sharedfiles/filedetails/?id=2398112113 4. Gloating about his exploiting. (All you had to do was bring a specific round of ammo to kill me under ground where I would'nt be spotted if you didn't scan the area.) LOL! https://steamcommunity.com/sharedfiles/filedetails/?id=2398114055