The head isn't normally part of the hitbox, so I believe the crouching sprite makes it so the head is just inside the hitbox.
I'm pretty sure I unknowingly tested this theory. Earlier in a pug, I shot at a heavy's head as sniper, and it shot over. Trog is
probably correct.
I know, I know... But it makes lag. What the heck?
I think that's just you connection, Mr. Tea N' Crumpets.
Most of this update was synchronizing, bug fixes, visual effects, etc. It would be actually nice to see a 'substantial' update, other than improving visuals and sound effects. Nothing too game breaking, but something that changes the game in a certain.. manner.