Nubbyzor of Whisperwind quickly pointed out that if the raid leader is saved to the instance you join their raid ID. This has happened since the dawn of raid timers. People have been mislead into joining raids in progress and cannot get a second shot at a heroic if their group is under par. Heroics aren't really a big deal, if your group fails, you can try again tomorrow. It's lame, but it's only one day. The week-long timer on raids makes this a little bit harder to swallow.