I always used the rule that you could always tell when your DO was lying to you because you could hear him down the phone. I had "duff gen" on 2 occassions early on in my career which led to me not buying a house during my first tour - had I done so I would not have had a mortgage for many years now!
The "contingencies of the Service" was quoted to me with the suggestion of a dismissive shrug. I've not trusted them since, and do not see any evidence to do so in the future.