This episode showed several confirmations of this. The Others killed off Dharma, Ben killed his Dad, and clearly, Ben shot Locke. So when Ben says they aren't killers, he's lying. And even personally.

Well we definitely know Ben is a killer and a huge liar and I hope he suffers.

Amen. We pretty much knew Ben was a liar from when we met him in S2 but TPTB had said we might change our opinion of the Others once we are shown more about them. My opinion has only changed for the worse - they are not only killers, they conducted genocide. So when they assert "we're the good guys" I don't buy it.