I can't definitively prove it in Destiny without private matches, or someone I know being on the other team, but it certainly worked well in Halo. Assuming Bungie uses the same ideas in regards to hitboxes, the head has its own hitbox (a lot of games do that) but Bungie makes their characters animate looking down interesting, their heads move down when they look down, and I think they also raise their arms because a large weapon cannot just phase through the floor, so it's a interesting detail. I'd assume their head hitboxes move down as well, like it does in Halo, so sniping becomes infinitely more difficult.

Absolutely