He should have been touching the wheel. Tesla nags you if you don't exert varying force on the wheel, so it's not possible for him to not touch the wheel during the trip unless he was using some sort of defeat device.

I've had this experience with Subarus. And it's fucking annoying. If the car is tracking where it should go, why do I need to put force on the wheel? It's like I have to keep steering it slightly the wrong way so that it fights back against me just a bit to keep itself in the lane. Otherwise, it thinks my hands aren't on the wheel and bitches the whole time. My hands ARE on the wheel, there's just been zero reason for me to put any turning force on it.

It does for Autosteer but not for FSD, which only requires that you look ahead at the road and if you do so then you don't need to touch the wheel at all.

It only nags you if the cabin-facing camera can't tell whether you're keeping your eyes on the road now.

It barely nags at you if at all. I haven't seen it nag at me in a long time when I take my hand off the wheel. I assume it's because of the camera watching the driver that they allow it but I'm not sure.

That’s no longer true. As long as the car has a cabin camera (which has been the case since the Model 3 came out), it will only nag you if it can’t see your eyes or you’re clearly distracted.