In the second half of a brutally physical game between the Heat and Pacers, LeBron James drove into Roy Hibbert -- known for being a rim protector with his so-called "verticality," the rule stipulation that allows him to go straight up and absorb contact without a foul.
James' elbow went high, whether to make contact or to try and get around Hibbert for the layup, and hit Hibbert under the chin. Hibbert landed and seemed disoriented. He tried to get up, and then fell back down.
James was charged with an offensive flagrant foul, which is rare.
Hibbert would go to the bench, be treated, leave for the locker room, then return to shoot the free throws for the flagrant. He would then leave again, presumably for the NBA's concussion test protocol, and then return to the game. He eventually closed out on Chris Bosh on the Heat's last second game-winning attempt.
Here's a shot of the elbow.