Speaking from experience, the majority of staff in the careers office aren't medical experts, and even with those with medical training have to stick to what they can say as a recruiter. They don't see your records, so they don't know to say something as specific as you've a low chance of redislocation.
That said, if you want to appeal, all you can do is present facts. Stick to stating you have been discharged by your consultant and physio and have a full range of movement. Don't use the anecdote from the careers office.
It's on a case-by-case basis, so it doesn't matter how other people have managed their appeals. It's enough to say that those who are successful in getting the decision changed present new information, such as a misdiagnosis or a mistake in their medical records. Just bear in mind you're not doing that, you are asking the RAF to go against policy. There will be people applying that meet all the requirements so they can afford to be choosy.