If you're trying to make sense of what happened, here's the gist of it.
1. John Henson picks up his first technical foul with 3:43 left in the fourth quarter.
2. With five seconds left and Milwaukee headed for a win, Henson comes from behind to crush Matt Barnes' layup out of bounds.
3. A double technical is issued on Henson and Barnes because Henson stares down Barnes and Barnes is jawing right back. That's Henson's second technical and he's ejected.
4. Barnes continues arguing with the officials. He does NOT receive a second technical, but he is subbed out and immediately leaves the floor.
Barnes proceeds to run down the same tunnel as Henson, leading to the Bucks' announcer Gus Johnson to speculate wildly (and somewhat dangerously) that Barnes is about to crash the Bucks' locker room to fight Henson. This did not happen, as confirmed by reporters at the game, although Barnes either made it to the locker room's door or all the way inside, according to different reports.
Hearing that Barnes got as far down the hall as the door to the #Bucks' locker room but there was no off-court confrontation with anyone.
— Pratik Patel (@PatelESPN) March 18, 2016
Several sources said Barnes entered Bucks locker room after game looking for Henson.
— Gery Woelfel (@GeryWoelfel) March 18, 2016
The game was incredibly scrappy for the entire second half. Barnes had scored 16 points in the first quarter, but was held to just four the rest of it, which may have left him frustrated. Barnes is also, of course, a very high strung player, to put it nicely. He infamously drove to Los Angeles to attack Derek Fisher regarding a dispute about a woman they both had a relationship with.
Despite the way it looks, there's no indication Barnes left the floor intending to do anything but head to his team's locker room, and if there was any ulterior motives, there is ample security to prevent something like that from happening. He did leave the arena with two guards escorting him.
Matt Barnes just left the arena. He had two security people beside him.
— Aron Yohannes (@AronYohannes) March 18, 2016
With that said, it's possible the NBA still passes down additional punishment in terms of fines or possibly even a suspension.