Originally Posted by
floridaCFII
A large number of pilot deviations (or perhaps violations is the correct term) occur because pilots admit fault over the radio and/or on the phone during a follow-up call. If you're off altitude and asked to verify altitude, just say the altitude you're supposed to be at... "Let me recycle my Mode C for you" (of course it's magically working right when it turns back on

).
On another note... there's no need to call the number they give you. Call your attorney instead.
I agree with you that it's best not to volunteer any information. That being said, if an altitude deviation is being investigated they use the only source of information that's available to them - which is the altitude reported by the transponder...
Now, if you wrote up the transponder right after the flight saying "altitude reported to me by the ATC seems to be 300 feet off from what the altimeter is showing" you might have saved the day... or so I've heard...