You can tell when people are afk'ing vs. having computer issues because they're still lotting on drops the entire run.
If your screen is frozen or you can't control your character you'd still have to choose to do nothing about it for ten minutes. People that truly D/C don't hang around, they're gone in a flash.
I've forgotten what ship I was in a few times and accidentally queued up in a Tuffli but when I do that I leave the match immediately so I can be replaced. There's no excuse for that type of leeching either.
My e-mail is full of "solved" replies concerning this issue. I've probably sent in fifty or more tickets mostly from Colony Invasion. At least I'm getting replies now, I used to think nobody even looked.