The company has always taken any sort of flagrant disregard of their NRSA travel guidelines very seriously. And yes, employees do report such behaviors.

I've seen:

2009 JFK-SFO: Buddy pass rider (not active employee/retiree/defendant) screamed at GA for getting Y instead of F. Conversation quickly got to man calling said GA an "idiot". Talked with GA one week later. Sponsoring employees pass travel privledges were suspended for 12 months.

2010 NRT United First lounge: Drunk 20-ish looking dependent kid got reprimanded for demanding entry into the UFL. Told he was risking his father's NRSA privledges with the type of tone he was using. Asked NRT agent about 3 months later what happened...she instantly remembered and with a grin told me that not only was he kid denied boarding for his NRT-HKG leg, but his fakers pass privledges were suspended for 12 months.

2007 SFO-PEK: Visibly intoxicated employee caused a scene at gate for not receiving F or C. Saw him try and lunge for GAs throat with hand. Not only denied boarding and offloaded from Y, but had SFPD escort him away in cuffs. His pass travel was suspended indefinitely, and I later heard was forced to resign.

These are just about half of the events I've whitnessed over he years. UAL takes this very seriously.