Sargs,
You are right, however be very wary about taking career advice over RoS etc over the 'phone. Even from the God-that-is-the-desky. The desky might not know every finest detail, sometimes those micro details can be painful.
There is plenty in print in JSPs etc, and that is what the RAF will hold you to, not some verbal agreement made by a previous desky who may be long gone.
There are some very helpful Terms of Service people who can give you the exact low-down on what you're really signed in for.
Also double and triple check with the pensions lot too!
However if there is anything that could be contentious, get the other party to send an email and print it out.