Freeman crossed the line, unzipped her suit, crouched down on her haunches, shook her head, put her hand up to her face and closed her eyes.
Australia saw it as her being overcome with emotion. After all, winning Olympic gold was something Freeman had dreamt of doing for years. But Australia was wrong.
Speaking to Mark Howard in an episode of the broadcaster's podcast series The Howie Games, available on PodcastOne, Freeman opened up about why she reacted the way she did after her win. She wasn't emotional or overwhelmed - she was disappointed.
"Another thing that burns away at me is I know I could have run faster than what I actually have, but that's fine," Freeman tells Howard.
"I actually crossed the line, looked across at the time - 49.11 (seconds) - I was immediately disappointed because I would have loved to have run 48 (seconds).
"I just remember leaning over, putting my hands around my knees and just shaking my head."
Howard asked: "So that head shake was disappointment at your time?"
"Yeah," Freeman replied. "I was not happy.
"It's a mighty occasion. I don't mean to sound like a Debbie Downer, but that's just who I am."
Freeman's disappointment was mixed with surprise that none of her rivals took the fight to her when she was down on pace.
Usain Bolt sledged his fellow runners after winning gold in the 200m event at the 2016 Rio Olympics, saying he would have run faster if those alongside him had been able to push him harder. Freeman was clearly being honest rather than disrespectful, but you get the feeling she was thinking the same thing.
"I was surprised nobody forced it, pushed it a bit," Freeman says.
"I was surprised that Lorraine Graham from Jamaica who got the silver didn't go ahead but in that moment people are hesitant because no one really, really committed against me. Nobody really believed they could beat me.
"When I look back at the footage, nobody really believed that they could win and I think it shows because the pace at which I was running when I was back in the field - it shouldn't have been that way. For a real contest there should have been more of a fight earlier on for that stage of the race. That wasn't the case."
One person who may have pushed Freeman - had she been there - was Marie-Jose Perec. The Frenchwoman won gold in the 200m and 400m in Atlanta and in the 400m in Barcelona in 1992, but exited the Sydney Games in bizarre circumstances.
She left Sydney days before the opening ceremony and later claimed it was because she was being threatened and harassed in the lead-up to the Olympics. But many believe Perec simply felt the pressure and freaked out.
"I was really sad," Freeman says of Perec's withdrawal. "My initial reaction was, 'That's too bad,' because I would really have loved to have had the chance to have raced her and of course to have beaten her.
"But I'll never have that chance and that's one thing that really gets to me, always."
On that September day nearly 17 years ago Freeman's fellow runners may not have believed in themselves, but she sure did. The proud indigenous Australian had the natural talent but perhaps more importantly, the killer instinct to boot.
"I wanted to be an Olympic champion and I didn't care about the goings-on around me," Freeman tells Howard. "In my heart and with all of my soul I was ready, willing and I was very able.
"I had a deadly sense of self-belief. I'd go to another level and say I had a deadly sense of self-conviction where you can say whatever you want, you can do whatever you want but you're not going to touch me.
"No one could ever get into this sacred space that only I'm allowed in.
"You really do live your life like you are the only person in the world."
Freeman tells Howard how calm she was during the 2000 Olympics and how little she was affected by pressure. "It's easy, it's really easy, Howie," she says as she described being in her "natural element", completely confident all her work would pay off when the time came.
"It was the most natural space for me to be in and to move through."
But Freeman does deviate from the narrative that details her aura of invincibility to reveal there were a couple of times when she wasn't entirely in control of everything. One such time was several months before the Games when she just lost it without knowing why.
"I had a little panic attack that lasted for three or four seconds - a very private moment - where I thought, 'F*** this, I can't do this, why am I doing this?'" Freeman says.
"I remember my cats were keeping me company and I was having a conversation with my cats.
"I just wanted to not be here, and it didn't last for very long - I think it's very natural for the body to consider other options.
"I still had a very acute awareness of the situation, of the reality that my life was. Just because I act all, 'La, la, la, la, la' and nonchalant it doesn't mean I'm not aware."
The other was the feeling she says every runner experiences on their way to the call room.
"You feel like you're a lamb going off to slaughter, and I mean that," Freeman says. "You're so vulnerable and it's like, 'Oh s***, oh s***, oh s***.'
"I felt scared - not scared where everything's falling apart - it's a feeling of, 'This is it, there's no turning back.'"
Once Freeman was on the track in front of 110,000 screaming fans, that "deadly" self-belief took over. The rest is history.
