Locke has always had his own agenda and that has never changed. Even when Frenchy women told him the others were coming and everyone was in danger is priority was to go down and explore the hatch rather than go back and keep the 'Losties" safe overnight. During S1 Locks first instinct was never to help them but rather teach self awareness and influence the "Losties" to face their fears. Since then Lock has become stranger and more distant as if he wasn’t enough already.

I just can’t get over the whole Tom and Lock connection. I hope this gets answered in the next episode.