How is the sniper's life threatened?

The sniper's life is threatened when he is gravely wounded in the arm, since he can no longer shoot his rifle.
Liam O’Flaherty's story of the Irish Civil War pits countryman against countryman. The IRA (the Irish Republican Army) is a paramilitary organization to which the main character belongs. This organization wants to force the British from the northern part of the country. If this goal is attained, Ireland will no longer be split in its loyalties. But North Ireland fights to remain a free state.
As the sniper lies in pain, after having cleaned his wound where the bullet is lodged in one of the bones of his arm, the man realizes that he must not be on the roof when morning comes, for the other sniper is watching for him to try and escape, and he can no longer use his rifle, because making any movement of his injured arm is extremely painful. Moreover, the bone is fractured, rendering him unable to hold a weapon that is as heavy as a rifle. Now he is very vulnerable. His only chance is to devise a trick to cause the enemy sniper to stand up. He does create a successful ruse, and he kills the other man. But once he is on the street and turns over the body of the other sniper whom he was able to shoot, the IRA sniper makes a tragic discovery.