So I decided to try a flash point last night on my now 37th level Shadow tank. But I decided not to tank so I cleared that checkbox and queued as DPS. (Aside: I cannot for the life of me figure out how people say the game mis-assigns them. it's never happened to me!)
Anyway, i get my group instantly and I see it's in progress. Uh oh. I double check that I'm flagged as DPS in the tool and I accept and travel.
First fight in, I know it's trouble.
After the second fight in, I post, "Sorry guys, this won't be worth the repair bills." and /leave.
I could have helped them. I could have taught them the fights and the strategies and shown them the optional skips. I could have flipped over to tanking or even just used more of my tanking skills to keep the adds off the healer because the tank was clearly not capable of doing that. But, repair bills being what they are, my decision was clear.