i did said, not all fights!!!
i will give some examples:
- on the yahkmar fight, when a tank, SIMPLY IRRITATES one add then runs away from yahkmar to place adds all together in one spot so they can be killed "faster", tank looses aggro while the worm is still on is way and didnt reach the tank position yet, is the tank's fault??? (after the worm is in position is diferent)
- Against the sister in malice, if a tank looses aggro, the fault might be the tank, because in this case, the damage from bosses is little and the point is keeping them busy, so HERE YOU THROUGH everything you have to hold aggro on a sister (even use frenzy stance)
- against the crabs in ardashir, throw all aggro tools and tell what happens, because i dont know
- against thoth-amon, if he is attacking you, through all your aggro tools at him the whole fight then tell me if you survived as boss target the whole time!!!
- in HoC try solo tanking the artificier if someone on group fails to use the forge as intended, then report
many other examples....
as i said and repeat to OP, try practicing with people that you know and have some kind of exp, that way you will know better who's fault is, even the rest of the group says it
P.S.: once with a friend of mine (DT full geared and AA, plus lots of exp) i stole aggro more than once with my barb on the same boss, who's fault was it???? (i tell you later if you want to know, and by the way we wont the fight with no wipe
)