Of course Nevill's height has everything to do with it.
No Yellow Pages would not have been deep enough to account for the height differential between Nevill and his assailant.
Height is only relevant if nevill is shot in the head in an upright position. I.e standing
Even then with the point .22, it only weighs between eight and ten pounds. Which makes it pretty versatile. ( obviously depending on your physical capacity of course. It would have been no problem for Jeremy, perhaps cumbersome for Shelia
Nevill had sustained many injuries, including rifle blows and numerous lacerations. It's quite safe to say that before the final four head shots he was probably almost beaten into submission as well as already being shot four times. Which would mean he would have been staggering, crouching or even floor bound.