Bah, you aren't in the right angry-mob mindset. Circumstances don't matter! Zone doesn't matter! Mob levels don't matter! Facts don't matter!
Now repeat that mantra a few hundred times and come back ready to nerf anything that looks at you cross-eyed!
I had some amazing parse once, not 21k high, but it was like 10k for about 20 minutes flat-out. During a bonus xp weekend about 6 months ago or so, a group of friends wanted to try the FC raid zone, specifically the aug event that spawns limitless zombie type mobs. I found a fantastic location to shove myself into a corner and manage to snag all the mobs as they came for us. It was a couple hundred mobs by the time we were done there.
It was good xp, but if anything went wrong at all we were toast, lol. I had a bot cleric spam healing me, and I was helping heal as I could with burst and going through nearly all of my defensive options and refreshing as I went. Still, the parse was amazing. But I lost that hard drive about a month later so I don't have it anymore
.
The funny part was I was still outparsed by the ranger in my group.