While working through Sons of Gruumsh, my PCs were captured and one was killed. The player created a rebellious half-orc shaman working against the Bad Guys from within, which was a perfect hook to, one, spring the PCs from their cells, and two, provide them with a glut of potions of cure wounds to get them back and their feet and help sustain them through the (very tough) finale.
So I gave the new PC a case of 12 potions, created by one of the Bad Guys and intended for troops in the keep.
For some reason that I'll never understand, the player doled out the potions with extreme stinginess, and as a result the party was wiped out. It's not like the player was being deliberately greedy or deceptive ... it's as if it just never occurred to him that it would be safer and wiser to distribute the potions among the group.
Dunno if this is what you're looking for, but it's all I've got. I don't allow Evil alignments for PCs, and I draw the line at party conflict that turns lethal, so player versus player action just doesn't happen. We of course use the ol' fireball the rogue with Evasion trick, but we're as careful with it as in-character knowledge allows.