is this a foul?

[rulesmaven]

Is it universally accepted when deciding whether there is disadvantage on the second play that the disadvantage must be caused by the illegal contact?

If the defender cannot keep himself in sufficient control to avoid contact (whether that contact ultimately be light or hard), might the defender have gained an illegal advantage by his hindrance of the shot? Put another way, in defending the shot, the defender must keep himself in a position where he does not make illegal contact, and if he does not do so, did he not gain an advantage by hindering the shot illegally? I think of this type of advantage most often when the defender comes a little out of control at the shooter; the shooter gets the ball off cleanly but perhaps not as accurately because he had to shoot over an out of control player. Whether the illegal contact before the shooter returns to the floor is light or hard doesn't seem to always answer the question.