It's a pilot. Did you expect him to walk?
I have a little experience with the AF. It was a joke.The junior guy isn’t obliged to salute an officer in or on a vehicle, or on a bike or motorcycle unless that senior officer is flying a flag with rank in it.
When I was enlisted, we didn’t have those (actually we didn’t even have cell phones, they weren’t invented yet), but I would have just said hi, or waived.