Sayid sinking the sub was MIB’s plan all along by Magnus Hanso

When Sayid grabs the bomb and runs away from Sawyer, Jack, and company, he isn’t doing it to protect them as it might have seemed. Sayid sacrificed himself for MIB in order to sink the submarine and kill some of the candidates, without him grabbing the bomb and running away from Sawyer, it wouldn’t have gone off.

Jack was totally right when he said that nothing would happen if they just let the bomb timer expire. MIB can’t kill them, but they can kill each other. What they failed to remember is that the candidates can’t kill themselves either. Sawyer pulled the wrong cord on the bomb and caused the timer to accelerate. If Sawyer were in the lethal blast radius of the bomb when the timer hit 0:00, it wouldn’t have gone off exactly the same way Jack’s dynamite didn’t go off in the Black Rock because Sawyer can’t kill himself. Sayid knew that the bomb wasn’t going to go off because Sawyer would be killing himself, so he grabbed the bomb and ran away from Sawyer to allow it to explode.

Another possibility is that Sayid was valiantly trying to save everyone else without even realizing that he was actually enabling the bomb to explode, but I think that this was all part of MIB’s master plan.