He immediately came back up after looking through his optics and located the enemy, engaged him and killed him by returning fire with his machine gun.
Strange detail, there's something lacking in this article. The loader's position has a machine gun, the TC's position has the periscope for observation. Did he use the TC override and slew the turret around and use the coaxial machine gun?
It was then Jacob had a feeling that someone was watching him. He looked back over his shoulder and saw somebody approximately 500 meters away. The man proceeded to fire a rocket-propelled grenade at the tank.
Bad idea. The most trained, skilled RPG gunners are good about to about to 300 meters, anything after that is impossible to predict. The best tactic would be to lob many of them up at that distance so that they detonate in the air like improvised mortars above the target.
A British commander came up to Jacob and thanked him for killing the sniper. The sniper had killed five of his men.

This part of the story is all but glossed over.