I once got into an argument with a tank over the efficacy of Cure 1 versus Cure 2 back when Keeper of the Lake was still fresh content. The guy never died but was understandably frustrated with little nooblet me because I somehow got it into my brain that Cure 1 was better than Cure 2 in every situation because it cast faster. Thus while the tank never died, he came VERY close several times. Needless to say once I realized how stupid I was being I about died of embarrassment.
Another one would be trying to run and explain mechanics in a raid and inevitably dying to those very mechanics because my attention was on typing, and not, you know, actually doing what I was supposed to do. So many rezzes of shame.