Counter-anecdote: I've played a game where the developer included a bug that gave other players arbitrary code execution on my PC and left it online while fixing the bug. I've never launched it since and had owned it less than 48 hours. Steam rejected my refund.

This is very good to know!

I always used the "doesn't work on my system". Though, most of the games I've refunded were really not working on Linux the way I'd like and I just didn't want to hack around or have to reboot into Windows for that game.