I'm paraphrasing here, but Mikhail said that he was "fortunate that the security fence wasn't set to a lethal level". He was also fortunate that Kate is a lousy coroner.
As for the episode itself, my immediate reaction was "HOLY SHIAT! THAT IS SOME SERIOUSLY FUCKED UP SHIAT!" but in a satisfied way.
Ben first gassing his Dad, and then collaborating in the massacre of the entire Dharma village? Damn! Seeing the bodies lying around the compound was reminiscent of latent images from the Jonestown massacre, and I bet that was intentional. To see the mass grave and have Locke dying on top of it was absolutely chilling. He'll be back though in some form or another. That's a moment I'm looking forward to.
Jacob? Who knows? I think Medusa is right in that it represents the island, even if it does turn out to be man made. I wonder if he (it?) is related to the smoke monster. A far-out theory I have, is that the sand-like material running in a line outside his shack is actually the smoke monster at rest. The force that is Jacob manipulates it like a sort of Island God.
Good idea about the Black Rock Ship being the descendants of the Hostiles!
I think one of the revelations unfolding is that the conflict between the Lost and the Others is one that has repeated itself over and over again back through hundreds of years. Let's start with the inhabitants who built the giant statues and ruins that we've seen fragments of, who are then purged by the shipwrecked survivors of the Black Rock. The Black Rock survivors become the inhabitants who are then purged by..?..and so on and so on up until the Dharma group gets taken out by the Hostiles.
One other thing: The episode implied that the Dharma group really was just an altruistic bunch of researchers, at least through Ben's understanding, but I'm hoping we'll find out that there was more to their operations than what we saw in the flashback.