not bad etiquette. Rules are if you leave the game, don't expect your credits to be there when you get back. I would just take a peek around, if no one looks like they were playing I'll gladly grab the free game.

On the other hand. I could see that just wanting to avoid the confrontation of some puffy noob would make you hesitate.

I've walked away when I've been on a time budget. I used to play TSPP on my lunchbreak, I'd put in a play, if I got the replay and a match, suddenly I was out of time. I'd leave it on there and walk away. I set some kids up with a few games when they were watching me, that's the ideal situation, get some young kids in for free - it's the same thing they do with crack.