He was a beginner, it was up to more experienced players and GM to clarify the nature of the game. Some games are supposed to be ruthless - tell a person they need to role-play an evil character, and what do you expect?
There's a few answers in the thread about how he basically revealed a troubling character attribute to his coworkers.
He acted as though he did not know or care what he did to upset them (evidenced by not apologising), and they now expect he is capable of acting the same way in other (professional and personal) situations.
He acted as though he did not know or care what he did to upset them (evidenced by not apologising), and they now expect he is capable of acting the same way in other (professional and personal) situations.