Lindsie Chrisley -- who's appeared on her parents' show, 'Chrisley Knows Best' -- is under the microscope of the Atlanta PD after a pal of her younger brother, Chase, filed a report this weekend following an altercation that went down Saturday night in the ATL.

According to the police report, obtained by TMZ, a guy named Austin Duriez claims he was at a bar in town where Lindsie also happened to be. He says, for some unexplained reason, she threw a glass with a drink at him -- which he says hit him in the head. He says he flagged down a bouncer and had her removed.

He says after she was bounced, Lindsie made a scene -- so he decided to leave. Austin called the cops the next day ... he wasn't sure if he wanted to press charges since Lindsie is his friend's sister. There's body cam footage of his interaction with cops -- and this all seems to harken back to the 2019 drama.

You'll recall ... the Chrisleys faced tax evasion charges at both the state and federal level -- mucked up further by allegations of an affair Todd claimed Lindsie had started with a tax official, which is what he believed led to the authorities getting the dirt they needed.

It was a whole ordeal, and essentially left Lindsie estranged from a good chunk of the family, including Chase.

As for what she has to say about all this ... her attorney, Musa Ghanayem, tells TMZ, yes, Lindsie may have gestured toward Austin as if to throw the drink ... and that if any liquid made contact, it was a tiny bit. The real perpetrator though, according to the lawyer, is Austin.

Ghanayem says Austin accosted Lindsie and her group at their table ... and then started to harass and intimidate them, to the point one of her friends had to push him off her. He also claims Austin was trying to snap pictures of them, and made them feel uncomfortable.