girls need for defence?

Hello

me and my girlfriend just broke up due to, well in my eyes something stupid and not really worth have an fight over..

we both play the game WoW *world of warcraft* and one night she got told off by the leader by doing something wrong, so far so good as the leader got the power to correct.

in this case the leader was acctuly wrong in what he said and i said that to my girl of course.. so after a few hours she got more and more "pissy" with me and i didn't really understand what i had done wrong so i asked her, and she went completly crazy over me not deffending her against the leaders "bitch" at her..

is this really something to fight over? that some guy i don't know age or place he lives says something "bad" about my girlfriend and i should make an havoc over the internet?

someone please help me here as im pretty clueless really..=/