Not unreasonable. If his arm was in front of his torso, bullet could easily have entered his arm, exited, then penetrated the “backstop” of his torso: 3 (potentially 4, if it then exited) holes from one bullet.
Heck, if his arm was also bent up, could have entered/exited fore arm, entered/exited upper arm, then entered/exited torso - 6 holes, one shot.
Straight count of N holes is not proof of N shots.
Anyhow the point is this stuff aint so hard to figure out.