fake leg and too nice for you own good ... aka there's no reason for a manipulative, competitive player to keep her.
But the timing was horrendous. Keeping Marty around is gonna bite the youth.
And to revisit the tribe reorganization: the older players were completely fucked by that decision. It created two tribes, both made up of majority young-tribe members. I'd be pissed. It's not Big Brother ... they shit on their own rulebook by doing that.