I noticed that melee attacks with a splitting axe don't line up with where a player is aiming. In my tests, I attack a wall with a splitting axe from a crouched and a standing position. The attack registers on the wall but the damage decals are up and to the left or right from where the cursor is.
I am uncertain if other melee weapons are affected by the same issue, but I wouldn't be surprised if they are. {F28350} {F28351} {F28352} {F28353}