Jack was the one who blindly put on the backpack the bad guy gave him! Jack was the one who didn't notice it was either a different backpack or was now several pounds heavier. Sawyer was the one who didn't trust SmokeLocke, while Jack went along with him to some extent, despite his babble about suddenly believing in their purpose and needing to stop SmokeLocke from leaving. He was fine with attacking Widmore's camp despite knowing nothing about him at the behest of the bad guy, and letting his friends fly off the island with Smokelocke. Since when did the smart move become blindly believing in the island and fate? That IS, after all, the M.O. of the guy who was duped, suckered, murdered and whose face is now worn by their archenemy. After getting Juliet killed with his irrational insistance on setting off a nuclear weapon on the word of a mentally-erratic man that it would make everything better, why would any reasonable man listen to his absurd and unsupported contention that the bomb will just stop? It's seems to be a damned if you do, damned if you don't thing - listen to Jack or ignore him, either way, a woman ends up dying pinned by twisted metal debris.

What should Sawyer have done to NOT get people killed? Tell Jack to make sure he doesn't carry any ticking bombs aboard the submarine? If Jack was Mr. Faith all of a sudden, why did he get on the sub? Why did he join the other candidates which would make killing them possible? According to Jack, Locke needed him, the Kwons, Sayid, Hurley & Sawyer to all be in one place to kill them, so why did he go with them just because Kate got shot? Where was his faith that they would all be fine then? Why not ensure BOTH women's safety by making little sis take Kate on board, and Jack stick to his "I'm not leaving" guns? NOT LEAVING was so important to him for this & the prior episode, so why did he get on a submarine as it was pulling away? Submarines are notorious as an example of "a contained place, with no means of escape," so how did Mr. Faith think he would be able to stay on the island while in a submarine that was fleeing the island as fast as it could?

And WTF, Jin? When you are a parent and your two or three year old child is currently in the custody of a murderous gangster, romantically dying at the side of your wife is simply not an option. You leave her, however regretfully, and do what you have to to get back to the kid. Punk move, Jin.