Weird Script Question

So today I was running bgs with some friends, and we got in a bg with an alliance warrior from Blackrock that I've seen before. This toon is nowhere near BiS, but he routinely does 2x - 3x the damage of all the other warriors in the bg. No SM. Mostly relentless pieces and some non-heroic pve pieces. Not even human, so not running the heroic double trinkets. And yet he out damaged everyone else in the bg, including their SM pallies and warriors by an enormous margin.

So here's the weird part. I'm reasonably sure that he's a scripter. Nothing new. There are plenty of them around. As soon as I saw him, I told my team to watch their logs to see if we can catch him and hit him with the ban hammer. But we can't, because he doesn't show up in our logs. The ONLY thing he ever registered on my log was piercing howl. Hit me over a dozen times with piercing howl, but *nothing* else. No melee strikes, no MS, no bladestorm, nothing. I asked my teammates to check their logs. Same thing. I was playing heals in this one, so you know he was focusing me. I died 8 times, which is way higher than average for me. Every time I died I checked the log, looking for a tell tale script, but he's just not there. Nothing except for piercing howl. Is there a script that removes one's damage from the log?? I don't understand. I can't think of another explanation. I would *really* like to catch this guy, but proof is hard to come by. I don't have a stream of it, but he did 2.5 million damage in a 15 man bg that wasn't that long to begin with. There were at least 6 BiS melee toons in this bg with SM, and the next highest SM toon did less than half that. It isn't "a bunch of players who donated for everything and can't play their class" type of thing. There are some really good players on both sides that got smoked by this guy in damage. Players with over 100k hk and players with 2k arena ratings on both sides. And this 6.0 warrior is doubling and tripling their damage, yet is a complete ghost in the logs.

Anyone?