Yeah, this feature was accidentally shown in the keynote.

Not always possible if law enforcement is breathing down your neck.

New iOS feature: tap the side button 5 times to disable biometrics until a passcode is entered again.

I saw that. Could still imagine not being able to do it in time.

True but at that point I think you'd have the same problems with touch ID.

This really seems like the argument to not use biometrics at all, not a specific issue with Face ID.

Agreed. I don't use it yet myself, so I'm good to go if I get tackled by security at the airport. ;)