Old vets wear their veterans in parades and such all the time. Clearly its not illegal.
Anyone can pick up a set of ACUs at a MilSurp store/yard sale/flea market and put patches on them.
People who have separated with an honorable discharge are authorized to wear their dress uniform at ceremonies or public events, but that’s about it.
This guy obviously never served a day in his life, and he most certainly never earned his Ranger tab. If you told a real Ranger to remove his tab or else, that guy would fight with everything he had.