tl;dr - There are are 3 likely suspects...
KNC, ghash or BTCGuild
I doubt it's Discus Fish since many of the people who would leave Eligius for calmer waters would not pick a Chinese centric pool
If it is not the above three, then it is something personal and/or jealously as the driving factor
KNC does not make sense to me - disrupting other pools does not improve their own since it is private. And there are more chinese miners than you think - its entirely likely some eligius users would be able to speak or translate it (but I agree it *may* not be enough to warrant the attack by discus fish)