The play happened during the third quarter of the matchup at Madison Square Garden. Porzingis went up for a lob after spinning diagonally across the lane.
Horford came to help contest, and after the ball went through the hoop he apparently thought it had missed entirely.
Meanwhile, Horford did have some redemption. The Celtics beat New York, 110-94, and Horford got a dunk of his own over Porzingis that looked pretty sweet: