Can Post Traumatic Stress Disorder ("PTSD") develop in non-combat situations? Can fighting against actions of fraud, waste and abuse?

The problem many have with stories like this, is they understand the shear number of disinterested parties that have nothing to gain and every thing to loose in such a purported wide spread collusion, it seems impossible to see it as real..Add to that, most times, like here we have but one side of the story, and third party told at that.
So is such a story possible? Yes, as anything is possible, its just most things are unlikely.

Are some susceptible to Post traumatic Stress disorder from non combat trauma? Yes
Has a person, or group gone to great lengths to cover up or discredit someone? Absolutely, and it almost always comes crashing down, because of my very first point. " shear number of disinterested parties that have nothing to gain and every thing to loose in such a purported wide spread collusion"
Eventually, the lie comes apart when someone, just one is no longer willing to further the lie, not even to ignore it.
There is no such thing as a secret..Only a truth that has not yet been told. The only perfect secret is when it is known only to one, and that one person dies having never told, written, emailed, phone called another.

Do people who jump behind a single, third party story often find them selfs later wishing they had not, when "The Rest Of The Story" comes out? Yes, all too often.

With the current administration there is no better time to have your comrade (what an interesting choice of terms) to come forward and seek justice. If it is as you say "the evidence proves that all the information provided by the service was totally false and that the service had eliminated my comrade to cover-up the mistakes within."
It should be a slam dunk case, the media will eat it up, a public trial will no doubt agree totally with your comrades evidence that proves that all the information provided by the service was totally false and that the service had eliminated my comrade to cover-up the mistakes. That is after what happens when there is such evidence.
Being vindicated will likely go a long way in your comrades recovery,,or at least certainly cant hurt I would think.. If it is the false allegations that caused the PTSD, having those allegations proven false by the "totally false" information your comrade now has evidence of...

Yes, PTSD is well documented outside of combat situations. It is also well documented as a non-permanent disorder.

PTSD is overdiagnosed - just like ADD ADHD we have allowed our medical field to look at the causes and fail to teach coping mechanisms, look at the current events another young shooter filled with drugs. It is a culture of big pharma in the name of helping us giving these drugs and a culture of acceptance. We have to make sure that you fill the narrative that everyone has PTSD, now it is almost a stigma for our returning soldiers. I served 35 years and saw lots of combat. With that lots of things that just part of the job. I currently am a full-time student getting another Grad degree, I talk to young soldiers all the time on campus, they are in school telling me about their rating and their benefits. I almost always have to ask what caused it, but it does lose some of its shine when I hear "we had a mortarman who had a tube blow up, so every time I fired a mortar I kept waiting for it to blow up" He now is receiving PTSD as a disability. He never saw it, and it never happened to him. There is a point where it would be a temporary issue, but we damage these young men and women by crippling them for a lifetime. There are real cases and they should be given EVERY treatment available but they are clouded by the large numbers of those who have learned the system and have a financial reason to simply never get better. Maybe temporary adjustments and re-evaluations would be part of a system to help our veterans, again care vs. a check. Combat isn't necessary at all, 1st responders, hospital workers, and many others are subjected to trauma. But we can cripple our soldiers by letting this be used for a lifetime. The care is available for a lifetime, but if they would take away the disability rating for most cases after an adjustment period they would empower these young heroes more often than not. I will share, that I do know what PTSD is, my father was a WW2 POW and I saw a man at almost 70 years old that you still couldn't touch when he was asleep, he masked it with booze for a decade and 2 divorces. When he finally met my mom and time had passed he was able to live the rest of his life normally. I never saw the effects but his ability to tell the stories and recover was inspiring. Personally, I had a daughter killed in a car accident, I was at the scene that night and identified her and my daughter in law. I see her in my mind almost every day in the back of the ambulance but we have to learn to cope. I was offered things to help (drugs) and I chose running and cycling to get myself where I could sleep. We need to engage and help our young soldiers, but we need to be honest too, we have allowed our political correctness in our society stop us from a little tough love. I liked to use the "Buck" example from the Band of Brothers mini-series. After diagnosed with combat fatigue he was treated and sent back, he returned after WW2 to prosecute the Robert Kennedy murderer and served on the California Court of Appeals as a judge.