Federighi then replied in an email: 'There are two ways, if you don't stare at the phone, it won't open. If while holding the phone out, you hold the buttons on both sides of the phone, it will temporarily disable FaceID '.
The way eyes closed was suggested by Apple in the introduction of iPhone X, that FaceID needs your attention to open the phone.
But the way to hold the 2 buttons on the phone is quite new. Whether it works or not depends on whether you are calm enough to push the buttons while being threatened with hijacking the phone. If not, just keep your eyes closed.