I would like an explanation on that as well. To tee off on return man even if he is faking to field the punt sounds like a penalty to me. I've never seen it happen but that blew me away for no flag
Walker, at that point in the play, was a blocker. He was nowhere near the kick nor had he signaled a fair catch. Smart play by Walker, but he hopped in the UL players way trying to sell it. It wasn't a bad hit, and he certainly wasn't defenseless. They called that one correctly.