A lot of missing details here, funny the headline makes the boss seem heartless for doing something so unprofessional when the text reveals it's because the author pestered him while he was on vacation.
I mean he's the manager who did not manage. At the end of the day, all people are humans. And if you feel like something is about to go wrong with your stability, it's a natural reaction to ask.
If nothing else, pestering the boss while on vacation is a bad sign.