Level 80s who single target groups of mobs

[Absurdity]

I use trusts to farm the dungeon glam while I do laundry. I don't even cast anything. I just stand there and move from mob pack to mob pack until its done. Usually about 25-30. Something is really wrong if you're in a dungeon of four real people and it takes 35minutes.

Yep, that's indeed the case, but not impossible.
I've probably had more terrible players in any ex/savage pug than I had in dungeons for about 6 months now but I also remember things like a ninja in amaurot that did less dps than you would do at level 60, it certainly can happen that you get players who are actually worse than bots.