Ambiguity in "The Sniper"

In the short story "The Sniper" the author uses the theme of ambiguity. The character in the story is in a war or battle. When he shoots a guy from the roof tops, as he ran down to the body and turned it over, he realizes it’s his brother: “Then the sniper turned over the dead body and looked into his brother’s face.” In this sentence I think the term brother is used as his actual brother, meaning he and his brother were on different sides of the war and he didn’t realize it was him after just shooting the other side he thought he’d take the risk and shoot the other sniper off guard. The author uses the theme of ambiguity.