No, hes taling about shooting guns on a steap hill. It is like you are actualy standing on stairs with edges, not a smooth surface. So when you try to shoot a gun when on hill, your shots will hit the "invisible wall" or probably the terain itself, instead of going to its designated targets.
Had a fight 2 days ago. 4v3. We all ended up emptying 2-3 60 cplis for the m4, only to find non of the bullets hit. Had to use my axe, and go melee :)
Dont think this is true only for the "elektro" kill or the "sniper hill" as they call it. The Dobryy hill north of elektro