The Will to Kill
One question has been bugging me really badly. Why could Ben kill Jacob, but Sayid couldn’t kill Flocke? Well, an answer recently came to me. What was the biggest difference between Ben and Sayid at that point? One thing I noticed was that Ben really wanted to kill Jacob. He was mad and upset, and hated Jacob at that point. Sayid, on the other hand, didn’t seem half as interested in wanting Flocke dead as he was in proving his goodness. And, at that point, Sayid’s scale was tipped towards evil, presumably the side Flocke is on. So, maybe they cannot be killed unless the attacker actually wants them dead. After all, Flocke could’ve made Ben kill Jacob, but he convinced him to manipulatively. So, that’s my idea.