The problem is two different kinds of jerks working in concert:

1: The jerks who HATE newbies and treat them like dirt.
2: The jerks who fly off the handle when a newbie makes a mistake, because said newbie didn't ADMIT they were new because of the threat of Jerk#1.

I just have a policy of roughly explaining the fights even if everyone swears they've done it before. Makes things go so much easier because you're bringing any stealth newbs up to speed too.