I've had DPS impatiently run forward and pull the next group of trash. Which I know the party can't handle.
If you do this to me, I will seriously go out of my way to avoid pulling aggro from you. Maybe the healer will spend time saving you. Maybe they won't. That's not my business. But if you wanna dive into it so eagerly, you can deal with the fallout. I used to try to save people who did this... I gave up. Screw 'em.
Seriously, nearly every time I run Qarn HM - and I'm not even i100 yet(i97) - some idiot DPS will go and pull all 3 of the last groups before the last boss. (2x groups of 2 knights, 1x golem). And I will either die, or lose aggro and let them die. And whether the party wipes is whether or not the healer stays focused and has the gear.
Pretty much every time I run it my DPS combo is NIN/BLM, to cause me maximum aggravation. I'm a PLD, we're not all that fantastic at holding trash aggro. I've had folks scream at me to "flash more" when I've already flashed so much I have to Riot Blade and get mana in order to do it again. And then they died.
Ooops.
Let me give them a /sad emote.
/ sorry, bit of a rant there