Sam visits the graveyard immediately upon finding out something happened there. He has to make sure Amy's grave isn't affected, or any of his friends' graves are affected for that matter.

The fact that they're not doesn't make him any less ticked off about the whole thing, but it at least doesn't make him more ticked off.

He hangs around in the vicinity, checking for familiar scents that could be associated with one of the three aliens. Maybe he can track it, if he finds it. Otherwise, he can just be bumped into by family and other Numbered, and eventually he'll wind up back at his daughter's place anyway. Still grumpy, but trying not to take it out on them.