Correct. As far as the FAA is concerned, there is no way they could prove the pilots were going to go to work the next day...the FAA would lose the case on appeal, so why bother?
The company is in the same boat...they can't punish the pilots for violating the 12 hour rule, cuz they did not go to work.
They can punish them for a schedule deviation which is probably not a firing offense for non-probation pilots. If they try to fire them for a 12 hour violation, the pilots will just claim they lost track of time and would have called in unfit when they realized their "mistake".