Had a couple interesting ones recently...
First, in HM Hammer Station: A DPS who, despite being somewhat decently geared for the flashpoint, apparently hadn't trained all their skills. We wiped at Sugar Smacks (the frog bonus boss) due to enrage and, upon returning from rez, the DPS asked if anyone had a Hutt statue so they could "train some more levels" before trying again. I dropped mine and then we proceeded to down the frog, but... seriously?!
Second, HM Cademimu, probably one of the funniest DPS pairs I have ever seen. Tank and I regularly group, and usually we like when we see both DPS are from the same guild... not this time. Two gunslingers, both decked out in 55 PVP gear. Should be fine, we thought. Just to be on the safe side, as usual, we spend the first couple group pulls doing a little CC with the dogs. Each time, I notice very little gunfire going off around me. As in... none. Tank's doing all the damage. Then, several seconds in, I finally see a Freighter Flyby. This goes on for each pull where we've done some CC, and from what I could tell the 'slingers were trading their flyby casts. Tank asks me (privately) if it was just him or if things were going slow, so I tell him what I had noticed and we agree to skip the CC and see what happens.
What happened was... suddenly no Freighter Flyby. However, not a lot of gunfire going off either. Things are going even slower. I've now noticed that one of the gunslingers (henceforth referred to as DPS 1) is not taking cover. Like, ever. I think he's throwing grenades on CD and occasionally hitting his default attack; he's not running out of energy hardly at all. I also notice he's doing a lot of running back and forth for no reason (something I had not previously noticed because he was always behind me). Pew pew pew, run run run, grenade, run run run, pew pew pew... just like that.
At this point we're at the first boss, so Tank asks if everyone knows the flashpoint. No response. A minute or two pass. Tank says, "Okaaaaay... is that a yes or a no? We're nice, we'll explain it if you need." DPS 1 says, "Ready." Tank and I have a little laugh and agree to see how it goes. Fight goes alright, despite DPS 1 almost dropping every blue circle bomb on at least one other person. I don't know if that boss enrages or not, but if he does, I'm pretty sure we cut it close.
We get to the Wookiee boss, and it's a Freighter Flyby party from both DPS as soon as the ugnaughts show up, which means they are both running around like headless chickens while the piggies eat their ankles. I've now realized that DPS 2 is going into cover and using skills, but using them veeeeeery slowly. Can't tell if she's specced heavily into Engineer (Sabotage? Middle tree) or not, but it looks like she's got some kind of hybrid build going on. Her energy levels are also barely being touched; it's almost like she is using a skill, waiting to refill, then using a skill... etc.
We tried coaxing them into a conversation where it'd be easy and polite to ask if they knew their classes well, but all we get is crickets. So, instead, Tank flat out asks them to step up their DPS if they can, because the bonus boss is no fun with low DPS. DPS 2 responds with, "We PVP, we can DPS lol." Umm... okay.
Bonus boss enrages. Tank and I manage to barely squeak out a victory without wiping, just barely; he dipped down into double digit HPs more than once at the end. Sigh... almost done though. I do what I can to politely explain that skills need to be executed faster in 55 HMs and that cover is really important for gunslingers. I even make a side-remark about how I "recently discovered" you could trade out the roll-to-cover skill for crouch on your quickbar, and you'll never end up where you don't want to be. (Not a recent discovery at all, but I was trying my best to not come off as snotty.) Still no response. I give up and cross my fingers for the rest of the run.
We get to the final boss and I can honestly say I have never had to run around the room so much. Even when it was my first time in there on HM, back when the boss was buggy as heck, and I didn't know exactly what I was doing and my own DPS/gear was crappy. I can honestly say I've never had to rez someone because they didn't move with the group (and no, I'm not talking about being stuck with shackles; I'm talking about flat out standing there going pew pew pew). And I can honestly say I've never watched someone die that way, get rezzed, and then do the same thing again. But, hey, at least he finally used cover.
Throwing down all the DPS I could muster at the end and managing to kill Ortol with a nut-kick was strangely satisfying, however.