To get them away from the monster maybe? At this point I don't put nothing past the writers, I wouldn't be surprised if Hank just wants to kill Heisenberg now.
I'm real curious as to what happens to Skyler and the kids tho. That painting has been buggin me since the second time they showed it. It's just makes me think that they leave New Mexico while Walt returns to finish off what he started.
which painting? I must have missed it.