The 40-year-old left the show just six hours into the first day, but all was apparently not as it seemed, with the PR queen taking to social media to defend herself in a lengthy post.
Roxy revealed she had actually fractured her hip and pelvis just six weeks before filming on the incredibly physically demanding show began.
Sharing photos of herself in hospital, she wrote: "To be candid I shouldn’t even need to post this - but I am left with no choice.
"To date I haven't shared these images because I don't think that it's necessary to share an accident where I was fortunate enough to get better when many would have sustained long term and irreparable damage.
"These photos were 6 weeks exactly before I left to join @sasaust7 - after reading the barrage of comments by people on my Instagram tonight I’ve decided - f**k it - I’ll post."
She continued, "For the f**k wits that have left comments on the post previous to this which I encourage you to read as it shows how alive and well these keyboard warriors are, let me explain how weak and fake I am.
"I fractured my hip and pelvis when on a horse for a job - the saddle slipped and I fell off. I got back on the horse so as not to bother the rest of the riders and disrupt their ride and then took myself to Emergency where I spent the next two days."
Roxy explained that she was out of action for six weeks laying on her back with daily shots, physiotherapy and appointments with orthopaedic surgeons.
"So if weak and pathetic is showing up to @sasaust7 because I had committed to it 6 months prior and put 6 days a week training into it no matter what my injuries were well then so be it.
"I think what it shows was, I had a commitment, I showed up and I tried my very best - which given the circumstances was a hell of a lot given my situation. I recall saying to my orthopaedic surgeon - 'I may have to fall out of a chopper can you suggest a way to do this with my fractures' his answer was simply 'don’t' - I did what I could but the reality is, my health is my number one priority with two children and a staff of 22 who rely on me - not a show for people’s entertainment and to give them something to troll / gossip about subsequently."
She finished by saying, "Having had cancer some three years ago I know that I didn’t need to take the chance of doing myself more harm. Anyway I think it simply shameful I had to post this & as I went to include my hospital discharge paperwork I stopped myself and thought - you know what - F**k them this is more than enough! I don’t need to prove anything to anyone I don’t know!"
Roxy quit the show after the group was instructed to submerge themselves in freezing water as punishment.
Some of the comments she received included things such as: "Geez, 6 hours!!! My wife was in labor longer than that. S**t effort."
Another comment read: "All the excuses in the world. So up herself. She couldn't take her handbags with her."
"Absolute failure. On all accounts," someone else wrote.
She then told the instructors that she wanted to leave, "I can’t do it. I actually can’t … My leg’s killing me. I can’t do it."
"It’s so f**king painful. I don’t want to give up," she said with the instructor describing her decision to leave as "unfortunate".
Roxy said: "I’ve always had the mindset of take every opportunity that comes your way. But people think that I can’t or won’t, or wouldn’t expect it. And that’s been every single thing that I’ve done."
"But for me, it doesn’t matter what everybody else thinks, it doesn’t matter if you get to day 12 or day two, the fact that I’ve actually taken the punt to do it with determination and grit no matter what, that’s enough for me."
Appearing on Triple M Sydney on Tuesday morning, Roxy spoke of the trolling she received, "What they failed to show on the TV was that I fractured my hip and pelvis six weeks previous. But forgetting all of that, I’m actually disgusted and upset that people are so mean to each other."
"Let’s not forget, this is a show for entertainment. I’m glad I left when I did because if others’ entertainment is Candace Warner bashing me in the back of the head when I’ve turned my head, do me a favour, I don’t need to be a part of that for other peoples entertainment."
Host Lawrence Mooney brought up the fact she spoke to her surgeon about the helicopter jump, adding, "Let's not play Roxy the victim here."
"I’m not playing the victim at all. I think what I’ve just said is that it’s very clear tall poppy syndrome is alive and well," Roxy responded.
Lawrence added, "Let’s not spend too much time talking about how we need to be kind. Roxy, you couldn’t make the grade last night and you dropped out and people just piled on. That’s part of the deal of reality TV."
"And you’re doing it too. I left because I had a fractured hip and pelvis and didn’t wish to put myself through any further potential injures," Roxy said.
He continued pushing her asking why she would go onto the show, to which she responded, "I got up and I showed up and that’s the most important thing to me."
"And you dropped out," he said.
Clearly unimpressed by the chat, Roxy said, "You know what, let’s leave this here because you’re doing exactly what the people on the internet are doing."
"I don’t actually do social media, mate," the host told her.
Before hanging up on the host she simply said, "I’m gonna leave that here."