I keep seeing stories like this one... Why are there so many jerks in this game? I mean, yeah I know its the internet, but still.
People who leave dungeons before 1 mob is even pulled because there is a SMN in the group
People who pull crap like the OP just said
I joined Ifrit today and before we were even done loading in a MNK troll pulled Ifrit to kill us all for no reason
People leaving dungeons because its someones first time. The game has barely been out two weeks...

I don't know why people think this is acceptable behavior but its not. I can only hope the people like this leave once subs kick in, or realize no one likes that crap attitude.
The only good thing that came of things like this is I appreciate how awesome my Free Company is. Running with them is far more enjoyable.