I think its due to that blue/white crystal buff.
A 200 BaM was hitting 999k at pap with the same blue/white buff active:
http://www.youtube.com/watch?v=t7SsyhWYars
Both classes are 200 so I didn't question them hitting the damage cap until I saw a 155 Evan hitting up to 999k per Illusion after using the buff:
http://channel.pandora.tv/channel/vi...ord=155&page=1
Does anyone know what the buff/effect does in kms?