Originally Posted by 2StgTurbine

That is no longer correct. If the automated system issued a report, the FAA can investigate it even if the controller didn't care or didn't even notice. Another common misconception is if ATC fails to correct your read back (IE, they clear you to 5,000 ft and you read back 3,000 ft and they don't say anything), you can also be violated for loss of separation.

Originally Posted by JamesNoBrakes

ATC is supposed to do certain things procedurally, but even if they forget or don't for some other reason, it doesn't change what happened in the first place. They don't have to say "possible pilot deviation", although they try to when it happens. NASA form is a good idea. Outcome is usually an Administrative Action Warning Notice. NASA form would waive the penalty (not the decision) if it went to a Legal Action, but that's rare for a simple pilot deviation. I believe the "alarm" ATC uses is 300', a good number to keep in the back of your head.

Mostly likely, if you haven't heard anything in a month, you probably won't hear about it at all. That's not an absolute, but it's usually the way it goes.