I think what he did was fine. If he's playing an evil, greedy, selfish person I think his actions were fine. He went in hoping to get all the loot to himself or at least first dibs. It didn't pan out. He died. Theses things happen.
I think too many people try to play too "optimally". "Oh, of course my greedy selfish guy is gonna share". Even if you planned on sharing maybe you just wanted to see it first.
If there is no risk, there is no fun. Not every adventurer is going to survive. There's a reason there's very few high level NPCs. It's hard to make it when there's so many ways to die.
I hate when my characters have died or when we hit the end of a campaign and can't play them any more. What I hate worse though is the amount of planning,meticulous researching, and brooding over what options to take.
Just have fun. Sometimes you should do things that are dangerous or suboptimal because that's what your character would do.
