I understand this as a wish for easier use of RPG's inside buildings.
By the way, I don't understand the red part, perhaps a small change in the grammar would help.
In IV, sometimes when you're trying to shoot someone who's too close to where you're shooting from (in this case, a window or ledge), you'll end up hitting the ledge instead, which is obviously instant death with an rpg. Other times, the rocket will spiral out of control after fired and hit something other than what you aimed at.