Well it sounds like he screwed himself...he should have kept his mouth shut, lawyered up and filled out a NASA report. But we can't put that sh** back in the horse now can we...
Sounds like his best bet is to explain the violation with a positive and educational outlook when he is inevitably asked about it during his interviews at the airlines. And keep a squeaky clean record from this point on.
EDIT: Why did the chief flight instructor want him to spill all the details?? What happened to taking the pilot's side against the feds?