Thanks, Mr. Potter, I do see your points (all of them) but have a different outlook to some of them.
Generation Y is a demographic group having birthdates generally agreed as being from early '80s to early 2000s and are typified in various ways including, but not limited to, the display of a sense of entitlement and narcissism. In my opinion, these traits show up in many of the events I hear about taking place in the cabin amongst the crew. I never get involved unless it transcends the usual pettiness and affects the safety of the flight.
Yes the purser shouldn't undermine the PIC but perhaps this purser saw herself as having been undermined by the PIC in the first place and in conjunction with a process of which the PIC knows little anyway. If he left her to it, it would probably turn out just fine. There are better ways to do things like that.