I'd agree to some degree if you could be confident that this was his actual routine, instead of a brainfart caused by nerves or distraction or any of a thousand

I'd agree to some degree if you could be confident that this was his actual routine, instead of a brainfart caused by nerves or distraction or any of a thousand other things that makes an interview environment different from a day-to-day work environment. I remember my dad getting annoyed at me when I was in high school because he asked me what time my soccer game was and I looked at my watch: he thought I was about to make a smart-ass joke[1] in the middle of us trying to figure out a schedule. That doesn't suggest that I don't know how calendars or timekeeping work: I was just distracted and glanced at my watch on autopilot. [1] I did make a lot of smart-ass jokes...