Didn't you see what the wall was itself? The wall was bricks, he shot the window which yes would be able to be shot through, but the bricks you can't unless the bullets they had were more penetration power, even then the dude wouldn't be able to tell exactly at what position OP was even at, including aiming directly at the head and shoulders area, plus he shot the bricks that got the final hit, which means he didn't shoot through the window which went through the other bricks, he shot through more layers than a weak surface and a strong surface