They argued back and forth, he said, and he had enough when she started calling him names, including "retard." He stopped the car, ended the ride on the app and told her she needed to get out.
She refused - repeatedly and belligerently.
"She kept saying she's an assistant DA and said, 'Who are they gonna believe you or me?' And I said, 'You know what, you're kind of right,' " Platt told ABC News. "So I took out my phone and I recorded it."
What followed was an exchange that would elicit a knowing nod from any Uber driver who's sworn off working Friday nights:
Platt: "I'm asking you politely, Ma'am, please step out of the vehicle."
Warner: "No, because I'm pissed the f*** off. Either drop me off at my house or we'll wait for the cops because I'm not wrong."
Platt: "I'm waiting for the cops."
Warner: "Then we'll wait for the cops. Jesus Christ, you're a f****** idiot in a stupid f****** hat. What a joke. Jesus Christ. I'll make sure Uber knows what a f****** joke you are.
Warner: And I want to go home so badly but you're so stupid. I want the cops to come so that they can f*** you up. That's what I want. Like you're such an idiot, I want the cops to come."
Platt: "Ma'am please."
Warner: (Mocking) "No ma'am please. Dude, everything's being recorded. I'm an assistant district attorney so shut the f*** up."
Warner: "So under the law, it's recklessly keeping me from where I was going and you have done that. You're kidnapping me. You're committing a third- to first-degree felony."
Platt, who also claims that Warner struck him at some point, ultimately gave the recording to the Dallas Morning News, which published it online.
Neither Platt nor Warner could be reached for comment.
Dallas County District Attorney Faith Johnson, announced on Facebook that she had "decided to terminate" Warner.
"Although criminal charges have not been filed, her behavior is contrary to this office's core principle of integrity, and it will not be tolerated," the statement said.
"As public servants, we represent the people of Dallas County and are examples of justice, professionalism, and ethical behavior both inside and outside of the courtroom."
Warner held a tearful news conference yesterday where she apologised on Tuesday. She told reporters she felt uncomfortable when Platt went a different way than she was used to and went into "fight or flight mode."
"I'm very sorry for the language I used. I'm not proud of it," she said, occasionally wiping away tears. "I appreciate being given the opportunity to give my side. I'm not trying to make any accusations against that driver. I don't know what's in his heart. I can tell you that not everything he said was true. I never touched him."
She added: "I'm not ever going to justify anything that I said. There's just a little bit more to it and I was wrong."
The 32-year-old joins the list of prominent people who got a public comeuppance after berating people with less-esteemed jobs.
The great equaliser appears to be nearly ubiquitous cellphones and other technology that can quickly capture and spread the ugliest moments of people with highly polished public images.
This year, for example, 28-year-old Philadelphia newscaster Colleen Campbell was arrested after attacking what appears to be the world's most patient police officer after the journalist was kicked out of a comedy club, according to the Philadelphia Inquirer.
The incident was captured on cellphone camera. In the video, Campbell spews a relentless, two-minute stream of profanity and insults. Afterward, the officer handcuffs and arrests her after she appears to spit on a manager and attempts to shove her shoe in his face.
"I work at a f****** news station, motherf*****. I work at PHL 17!" Campbell yells. "I'm not a f****** hood rat."
After Campbell was fired, ESPN reporter Britt McHenry came to her aid with all the empathy of someone who was publicly embarrassed after a similar potty-mouthed episode.
McHenry was apparently upset at a clerk while recovering her towed vehicle in Arlington, Va. She spewed insults, even after the clerk said the interaction was being recorded.
"I'm in the news, Sweetheart, and I will f****** sue this place," McHenry said, before calling the clerk a college dropout and insulting her appearance.
"Why, because I have a brain and you don't? Maybe if I was missing some teeth, they would hire me, huh? Cause I'm on television and you're in a f-- trailer. Lose some weight, baby girl."
