That's your view that I find totally unhealthy. If people are ready to stab each other in the back in the game, it's not different than IRL.
I like how your first sentence says my view is not healthy, and then the second establishes that you, too, cannot distinguish reality from fantasy.
If this happened to me? I'd laugh, and congratulate my friend on a job well done. Because he's
still my friend, OOC. Would I give him roles again, of course not. But hate him for it? For stealing fictional property?
Again, it's all in the spirit of the heist. If it's some douchebag doing it to specifically ruin your game...well, actually, the best thing you can do in that case, too, is to laugh it off and deny them tears. But if it's completely motivated by IC objectives, then yeah I can still be OOC friends with that guy. This is because I can distinguish between my
character, who has the space pixels, and
me, who has the fun. Character, me. Fantasy, reality. If someone betrays me in fantasy, I don't hate them in reality.
An IC hiest should not mean the end of an OOC friendship. It's pretty obvious that wasn't the intention in this particular one. But if the losing party isn't able to separate themselves from their character enough to step back and say "Hah, well played" then too bad for them.