From my experience I had an minor issue with a checkride. Like Coolhand said don't try and sugar coat it.
They will send you a form giving you full opportunity to explain yourself and situation. Use this as a time to investigate and reflect. For example I went and dug out my old PTS standard book and found exactly to the T what I had done wrong. I then went through and dotted all of my "I"s. As in "I"did this and "I"did that. Wrapped it up with a nice learning experience and I spell checked the thing and off it went.
Now I did run into a guy once who complained about getting a call but not the interview. After about three beers he conceded he filled this form out. 2 beers later he divulged what he remembers writing down. It was not good. He knew he messed up.