a problem that can occur with some players - and less-experienced/recently dinged 60's is following dps calls/managing own aggro
some ppl seem to think a 'good tank' should be able to hold all aggro no matter what....
in a lot of cases (and massively so in a lot of endgame instances) - watching your own aggro/dps calls/tactics are the key skills and make the diff between success/wipe in a lot of places
I've been in grps with a good tank - where the (insert dps class) has moaned about tank not keeping aggro - well it can be kinda hard sometimes - esp if ppl wade in immediately with some amazing dps and crit after crit...
wait a few secs, either wait for dps call or watch that the tank has got aggro first - eg you can see a cupla sunders under mob icon - (for a main boss, 5 sunders and u can usually start)
ppl have some way of reducing their own aggro - if ur in a boss-fight and u've scored a crit or 2 and its a hard-to-tank boss, wait a few secs before ur nxt attack or use whatever skill u have to ditch some aggro -
chucking out amazing dps can actually be a liability in endgame - UNLESS you follow dps calls and instructions carefully and make sure you manage your own aggro
ofc I'm not sayin you should just gently pat the nasty mob til it dies of boredom.... just be careful out there