Prolly just an accident on the dc, it happens easy enough, kill the power/internet cord to the router, and there goes everyone sharing it.
You state they dc'd to save there own hides, well, i've only seen one level 75 pl die to a banshee, and that was a rdm who converted w/o buffs on, and 1 mp <.<, no way under normal circumstances would a 75 be threatened by a banshee.
All and all, it's not really a good thing to slander these peeps because you think they screwed you on a qufim pt, it's qufim ffs <.<