I just can't see him redeeming himself enough for what he did. He should have told his friends what was going on and at least tried to save Walt by using more extreme means, in cooperation with his fellow Losties. I see why he might have felt there was no choice...but there is always a choice.

Unless he was actually being influenced by external forces. If there is mind control involved in the overall story arc it might be proven that it was not all his own decision. In this case I really don't think so, however. I think he's just a bastard.

__________________
"The Naked Gun!"

Frank Drebin remembers a lost love.

Frank: It's the same old story. Boy finds girl, boy loses girl, girl finds boy, boy forgets girl, boy remembers girl, girls dies in a tragic blimp accident over the Orange Bowl on New Year's Day.

Jane: Goodyear?

Frank: No, the worst.