Taking your comment literally, It says right in the book and in the movie that he did so there's not much to wonder about.
It does raise an interesting question - if the kid got a recorded warning for something as mild as "wow a hardcore WO in the cadets", what is the standard for acceptable insults? Is there a set of guidelines somewhere, because I can't find any mention of that standard in the site guidelines that the staff is insistent on everyone reading and understanding. It would be a lot easier to understand if there was a definite "insults will not be tolerated", so George's comment here has me confused.
Could someone please outline the policy on personal attacks and explain why George's comment here is acceptable but refering to someone as a "hardcore WO" is not?