Complaint
I am not sure were to complain about a player, I was in a silver match and hosting, it was public and Burningbend joined, it was on hydra, I was sniping and used grenades, he then decided to stand in...
Forum Discussion
You encountered a griefer. Their goal is the same as that of a forum troll, namely to draw reactions out of annoyed people. In that case, reacting is the worst thing to do. Just ignore the griefer.
For these sorts of situations I always have Fraps running. If someone's cheating or griefing, I can show evidence. Fortunately, I've mostly played with civilized players and never had to report one.
