Trump Staffer Britt McHenry Throws Drink at Fan at NBA Game, on Video

Britt McHenry was back in the sports spotlight Wednesday night ... but the former ESPN reporter wasn't calling the action, she was causing it ... throwing a drink on a fan and getting escorted out of an NBA game to a chorus of boos ... and it's all on video.

The current U.S. State Department press advisor got into a heated confrontation at the Washington Wizards' home opener ... and we obtained video showing her tossing a beverage at someone in the crowd.

But sources close to Britt tell TMZ there's more to the story ... claiming people sitting behind her and her male guest were making inappropriate comments about Kyle Kuzma's fiancée, Winnie Harlow ... and Britt responded. Kuzma used to play for the Wizards and now plays for the Milwaukee Bucks, their opponent in Wednesday's game.

Our sources don't recall exactly what prompted Britt to throw the drink, but say it was part of the confrontation ... and claim things were thrown at her, too. They also claim the group behind them were saying inappropriate and misogynistic things to Britt to instigate her.

Folks weren't exactly rolling out the red carpet for her exit ... several people began tossing rally towels in her direction as she made her way through the stands as boos rained down.

Britt, however, appeared unfazed by the hostile reception ... blowing kisses toward the crowd and waving on her way out ... though she was later captured on camera arguing with a security guard who was directing her to leave the building.

Despite the exchange, sources close to Britt insist she wasn't kicked out ... telling us she left on her own to head to the bar, while her male guest stayed behind and met up with her after the game.

The Wizards went on to defeat the Bucks, 128-116.