On Monday evening, Jayson Tatum and the Boston Celtics finally broke through and won their first championship of the modern era with a demolition of Luka Doncic and the Dallas Mavericks in Game 5 of the NBA Finals from Boston.

While Tatum put up the best game of his Finals career on Monday, registering 31 points and 11 assists, it wasn't quite enough to snatch the Finals MVP trophy from Celtics teammate Jaylen Brown, who was more consistent and efficient throughout the series.

One bizarre moment occurred after the conclusion of the game and the Celtics were spraying champagne in the locker room, at which point former Celtics forward Grant Williams, who ironically played for both the Celtics last year and the Mavericks for part of this year, was in the locker room partying it up with some of his old teammates in a very awkward scene.

One person who wasn't a fan of this decision was former NBA guard Austin Rivers, who recently took to his own Off Guard with Austin Rivers podcast, ironically featuring guest and current Williams teammate Seth Curry of the Charlotte Hornets, to discuss the incident.

“Grant Williams got traded from that place, and you got traded by the other team that was in the other locker room, you shouldn’t be there, no offense, right,” said Rivers, via Off Guard with Austin Rivers. “You were traded in a fashion that was like, bro they got much better when you left, and Dallas got much better when you left.

“Not to say anything against Grant, but it's like, there’s no way you should be in that locker room.”

Rivers also spoke on his own time playing for and then leaving a franchise that would go onto win an NBA Championship without him.

“I’ve been through it. I left Denver the next year they won, s—t, I thought it was going to happen again this year with Minnesota. I didn’t go to the finals to watch Denver win and go party with them in the locker room. Are you out of your f—-ing mind?” wondered Rivers.

“I was happy for them. I sent them all texts; I was happy for Coach Malone; I was happy for Mike, Aaron; I texted them. I’m not going to go party with you. You didn’t re-sign me. I did not win. Grant being in that locker room is strange as f—k, and I expected it 100%.”

An awkward Celtics scene

Boston Celtics guard Jaylen Brown (left) celebrates in the locker room after winning the 2024 NBA Finals against the Dallas Mavericks at TD Garden.
Elsa/Pool Photo-USA TODAY

As previously mentioned, Williams played for the Celtics and the Mavericks over the last couple of seasons and wasn't able to stick around long term with either organization. Williams did have the game of his life in the 2022 Eastern Conference semifinals Game 7 versus the Milwaukee Bucks to keep the Celtics' season alive.

But overall, he became more known for his antics–including provoking Jimmy Butler into a mammoth performance, telling Donovan Mitchell he would make two free throws in the clutch before proceeding to miss both, etc.–that left a bad taste in fans' mouths.