Hawks guard Kevin Huerter inbounded the ball with 4.7 seconds remaining and Atlanta down one point. Young set a screen on Cauley-Stein to create space for John Collins, but the Mavericks center knocked over the 6-foot-1 guard, temporarily taking him out of the play.
"I'm not going to run away from the ball with four seconds left and we're trying to win the game," Young told reporters postgame, according to ESPN's Tim MacMahon. "That's just the most frustrating part. Not really having an opportunity to make a play at the end is just really frustrating."
Huerter instead passed the ball to forward Danilo Gallinari, whose step-back jumper bounced off the rim. Young immediately marched up to an official after the buzzer, seemingly complaining he was left bleeding from the collision.
"In the game, the contact between Young and Cauley-Stein was deemed incidental and therefore we didn't have a whistle on the play," referee crew chief Josh Tiven told McMahon about the decision not to call a foul. "After reviewing the play postgame, we still feel that a no-call was the correct decision."
If a foul was called, the Hawks would have been awarded a free throw and then inbounded the ball again as the contact happened before the ball was thrown in.
"It was a perfect screen," Hawks head coach Lloyd Pierce said. "Willie Cauley-Stein ran Trae over, and that's a foul. It's a foul. It's why Trae was on the floor. It blows up our play. It's unfortunate.
"I thought our guys really competed. Trae was fouled. He falls on the floor. He gets hit in the nose. He set a great screen. I give him credit; he set a great screen. We tried to execute, and he did."