No, I've been on this forum for 16 years just to pretend...
I'm just not going to begrudge a kid for making a decision that he feels is best for his future after what he signed up for no longer exists. If this was some PhD candidate who came to a university to work under a professor, and then the professor left and took his research project with him nobody would call the student selfish for following the professor to his new school. This is the same thing. Z is making a decision he feels is best for his future career.
Let's be honest, a kid from Croatia didn't come here to play for UK. 12 months ago he probably couldn't point out Kentucky on a map. He came here to play for Cal and that's fine. Live and let live.