How does the sniper convince his enemy that he is dead?

The Republican sniper fakes his death in order to fool the enemy sniper from the Free Stater army.  
The protagonist sniper bravely puts his life at risk in order to shoot and kill the old woman and soldier in the armored vehicle. Unfortunately, he leaves himself slightly exposed in order to make those two shots. The enemy sniper shoots him in the right forearm. The wound is so bad that the sniper can no longer lift and aim his rifle. He must figure out a way to kill the other sniper, and is limited to using only one hand. 
The Republican sniper's plan is to fake his death. He takes off his cap and places it on the muzzle of his rifle. He then lifts the rifle so the cap is exposed to the enemy. The enemy sniper takes what he thinks is a head shot. The bullet goes through the cap, and immediately the sniper lets his good arm hang over the edge of the roof while holding the rifle. After a few seconds, he drops the rifle and lets his body's weight sag and drag his arm back over the roof.  
The Free Stater sniper now thinks his enemy is dead, so he stands up and exposes himself.  

He was now standing before a row of chimney pots, looking across, with his head clearly silhouetted against the western sky.

The Republican sniper then pulls out his sidearm and shoots the enemy sniper.