Why were the Bucks upset with the Pacers after the game on Dec. 13? Hint: It wasn't about a ball.

In the final moments of the In-Season Tournament semifinal at T-Mobile Arena in Las Vegas, Indiana Pacers guard Tyrese Haliburton knocked down a clinching three-pointer over the Milwaukee Bucks. He looked down at his wrist – a nod to Damian Lillard’s famous “Dame Time” end-of-game gesture – and sent the Bucks home early.

The Pacers won that game 128-119, their second victory over the Bucks in a month.

Haliburton dribbled out the clock, and Bucks players filed onto the court to shake hands and hug it out.

Afterward, Lillard was asked about Haliburton’s celebration.

“I learned as a kid, when you dish it out, you've got to be willing to take it,” the Bucks point guard began. “For as many times as I've done it to people, I can't be upset when somebody else does it, you know what I mean. I think that's also a sign of respect and acknowledgment for knowing my history and knowing what I do. I didn't mind it. It was what it was.”

He continued, though.

“I've also known that, you know, when you are having your moment, it's important to be careful, to be humble in your moments because you just never know how the tables are going to turn or when they are going to turn,” Lillard added. “I respected it. We shook hands after the game. I wasn't moved by it left or right.”

Milwaukee indeed turned the table six days later in a memorable game for several reasons. Giannis Antetokounmpo set the franchise records for points in a game. Damian Lillard became the NBA’s No. 5 all-time three-point shooter.

And then afterward frustrations boiled over into several heated discussions between the teams, which included Bucks players heading down the Indiana tunnel and conversations about what happened to the game ball.

But the root issue of it all for the Bucks was not about a ball, but ultimately about humility – or a perceived lack thereof – in a less celebratory moment on the part of the Pacers.

Giannis breaks Michael Redd’s record, Pacers unhappy

Following the Pacers runner-up finish in the In-Season Tournament, they came to Milwaukee on Dec. 13. The game was tight through the first 2 ½ quarters, but in the final minutes of the third the Bucks stretched an 8-point lead to 13. The Pacers cut it down to five at the beginning of the fourth, but behind Giannis Antetokounmpo’s dominating performance Milwaukee rebuilt its advantage to 18 with 6 minutes, 26 seconds left.

Indiana coach Rick Carlisle pulled starting guard Buddy Hield then.

Carlisle pulled key reserve Aaron Nesmith with 6:05 to go and sat down Haliburton and fellow starter Myles Turner and top reserve Ben Mathurin with 5:54 left and the Bucks up 17.

The Bucks’ starters remained in the game over the next two minutes, increasing the lead by two points as Antetokounmpo ultimately set a single-game franchise record with 58 points at the 3:25 mark and the Bucks up 131-112.

Milwaukee head coach Adrian Griffin then pulled his starters a second later.

Antetokounmpo acknowledged he was given the green light to break Michael Redd’s franchise record of 57 points. When Griffin was asked why he left the starters in for those roughly 2 ½ minutes after the Pacers’ starters had been pulled, the Bucks coach simply said there was too much time left for him to feel good about subbing them out considering how prolific Indiana’s offense is.

Sure enough, in the 79 seconds following the Bucks’ substitutions, the Pacers reserves cut the lead to 10 and Griffin called timeout with 2:05 left. The Bucks starters returned. Antetokounmpo would finish with 64 points, the final bucket an emphatic breakaway dunk with 26 seconds left.

Carlisle was asked after the game if he was surprised if Antetokounmpo had remained in as long as he did against his team’s substitutes.

"No point commenting on it," the Pacers coach said. "I think it's pretty obvious what the answer is."

Lillard dribbled out the clock, and Bucks players filed onto the court.

Pacers veteran guard Bruce Brown, the only regular still playing for Indiana, had words directed at Griffin and Pat Connaughton on the Bucks bench as he walked off towards his bench. Pacers guard and former Buck Jordan Nwora hugged some of his former teammates. Pacers rookie Oscar Tshiebwe also doubled back to the Bucks players.

Haliburton remained near the Indiana bench.

The rest of the team appeared to have left for the locker room.

Bucks upset at lack of handshakes

In the moments following the conclusion of the game, the television broadcast showed Bucks assistant coach Josh Oppenheimer having an animated conversation with Pacers assistant coaches Mike Weinar – who happened to have a game ball in his right arm – and Lloyd Pierce.

Haliburton was there also, and Thanasis Antetokounmpo ran over to him to shake hands. Haliburton briefly acknowledged it, and Antetokounmpo tossed up his hands and ran off.

The conversation between coaches and Haliburton continued, at which point Giannis Antetokounmpo left the postgame prayer circle at halfcourt to see what was happening. Khris Middleton and Jae Crowder also went over.

Middleton, who rarely expresses emotion, was heated in his conversation with the Pacers.

As those conversations about the lack of postgame handshakes were going on, Giannis Antetokounmpo suddenly bolted down the tunnel toward the Pacers locker room. He was tailed by Crowder, Thanasis Antetokounmpo, Cameron Payne and MarJon Beauchamp along with team security.

The players returned shortly thereafter, and Giannis Antetokounmpo immediately went to Haliburton and in a heated exchange could be seen telling the Oshkosh native that his team should’ve shaken hands on their way off the court, like the Bucks did in Las Vegas. The nature of Antetokounmpo’s comments were confirmed to the Journal Sentinel by multiple people who heard them.

Now, about the game ball.

The one Weinar left with was not the actual game ball but one of several available to be used during the game. Giannis Antetokounmpo didn’t know the game ball had already been retrieved by Bucks staff, so it ended up being part of the broader issue he and the other Bucks had with how the Pacers reacted to things postgame. Bucks sources insisted the ball was never the core issue of the postgame interactions.

The Antetokounmpos, Crowder, Payne and Beauchamp were not fined by the NBA for heading down the tunnel.

Bucks and Pacers to play two times in three days

Indiana returns Monday for the fourth meeting between the teams. Then, Milwaukee heads to Indianapolis on Wednesday for the regular season finale.

It’s a game where perhaps enough time as passed for emotions between the teams to have cooled, and the Journal Sentinel learned players from both teams communicated with one another after to further clarify and smooth the situations on Dec. 13.

After all, the teams did shake hands following the Bucks losses in Indiana on Nov. 9 and in Las Vegas.

But will it be easy to sweep it all under the rug? Milwaukee has gone 9-1 since losing in Las Vegas while the Pacers have gone 4-6. The Pacers still have a 2-1 series lead and the Dec. 13 game was heated prior to the post-game scenes:

• Giannis Antetokounmpo received a technical foul for knocking Haliburton to the floor after a dunk.

• Bobby Portis was ejected.

• Andre Jackson Jr. was given a technical.

• Aaron Nesmith was given a Flagrant 1 for a foul on Antetokounmpo and a separate technical.

• Pacers Obi Toppin, Ben Mathurin and Buddy Hield also received technical fouls.

"Nah, it's a new year man -- it's 2024," Portis said with a smile and a laugh when asked following Sunday's practice if there would be any carryover from that.

Instead, Portis highlighted Haliburton's play and Indiana's high-speed, prolific offense.

"For us it's all about just about getting better," he continued. "All about us taking that next step on a daily basis and worry about ourselves. Obviously getting into the season, obviously they're an in-division opponent and we obviously play them four times a year. This year it's gonna be five obviously with the In-Season Tournament in place and things like that. But it's just another game for us to go out there and get better, man, not worry about what happened weeks ago. We just worry about just trying to get a dub."

This article originally appeared on Milwaukee Journal Sentinel: What really happened for the Bucks to get upset with the Pacers?