I wonder how said mighty priest would feel if everyone in his raid macroed /cancelaura Divine Aegis /cancelaura Power Word: Shield into all their abilities.
Wow! I can imagine people doing this in LFR (because LFR is serious business), but not in a progression raid.
The sad/funny thing is that on farm such tomfoolery isn't unknown at all. But it's farm and you have to entertain yourself somehow. During progression it's completely unacceptable.