What can you infer about the sniper based on the way he dresses his wound?

The unnamed "Sniper," in Liam O'Flaherty's short story of the same name, is a participant in the Irish Civil War. The story takes place in 1920s Dublin (the site of an especially bloody series of battles that ended in the death of hundreds of both Republicans and Free Staters).
The story begins in medias res, and the sniper is seen loading his rife and eating voraciously. Here, the crude juxtaposition between fighting and eating is deliberate; the sniper is inured to the brutality of anonymous and arbitrary killing in the name of one's political party. We are told that the sniper is of the Republican party—an army known for its guerrilla tactics throughout the 20th and 21st centuries.
First, it is remarkable that the sniper keeps a "field dressing" with him (indicating that he anticipates the level of sacrifice represented by being hit). He "rips [it] open" with a knife. The dressing kit contains an iodine bottle, which he breaks in order to treat his wound. He ties the ends with his teeth, amid a "paroxysm of pain."
The sniper demonstrates superhuman resolve as a Republican and sniper, reassuming his sniping duties after the severe injury to his arm:

He bent the arm below the wound. The arm bent back easily. He ground his teeth to overcome the pain.

He is resilient and deliberate in his actions, despite suffering crippling pain that would have disenfranchised others in his position. The actions of this nameless protagonist is representative of the rare form of mercilessness and determination in the name of the Republican cause.