On a more serious note... there was a note that said if a skill exists In-Game and a fellow player has it, then the player must learn from his/her fellow player and no NPC teacher will come out. Even if the characters were diametrically opposed to one another IG-wise, this is still the case... correct?
Where was this note?
We'll never deny someone lower list teaching, although we prefer inter-PC interactions. If a character can't find anyone IG to teach him, they should note this by filling out the Event Recap form. We'll look at the situation, and determine if it warrants sending out an NPC Teacher.
Note that what happens IG is a separate issue. If you piss off your NPC teacher In-Game, that is YOUR problem.