If it's hax, it's the dumbest hax ever if it's giving the mob progressively weaker debuffs (probably lag anyway).
It's lag. It always happen to me when I can see Dancer effects on mobs in Campaign. They all show up in my log after the mob dies in a seemingly random order. Really annoying >_>
It's hax Rocl is lying he is protecting himself because he does this too
It's lag, I've seen it in Dynamis and Besieged with WSs. It's kinda funny seeing 8 Tachi: Gekkos for widely different numbers happen at once after the mob's already dead.
Use chat filters. It really helps.
I once saw the damage for a Sidewinder on Olla Pequena right after the killshot on Olla Grande.
It is indeed lag, and sometimes lag can cause your chat filters to break.