Well, I thought about that, and maybe the person could be an anonymous backup and PM the host, and the host do it for him? Problem with that is that the host would have to be really really active.
Having a person who has died rejoin the game typically won't work.
If their role wasn't revealed when they died, then they know someting no one else knows (what the role was that died). In addition to any information gained as a part of being that role.
If their role WAS revealed when they died, then like you said it would have to be the same faction, however then everyone would know their faction. Unfortunately once you're dead in a mafia game coming back in poses all kinds of issues.
EDIT: Or maybe PM another BrainDenizen who's not involved in the mafia to post it for them?
Edited by NickFleming, 28 August 2010 - 01:12 AM.