Ruling
Unsportsmanlike foul
Assessed by intent and the game situation, not just contact force. C2 often applies — contact during a fast break with no attempt to play the ball.
The defender makes no legitimate attempt to play the ball — the arm is directed at the attacker's torso, and the eyes never track the ball. Contact happens from behind during a fast break, with no defender left between the attacker and the basket.
The fact that the contact looks light doesn't matter: what's assessed is not the force of the hit but intent and the situation on the court. This matches criterion C2 — contact with a player advancing to the basket, with no attempt to play the ball.
Ruling: unsportsmanlike foul, two free throws, and the ball at the center line.
An educational opinion, not an official federation or FIBA ruling. Cannot be used to file a protest.