So when you land you can simply hold down on the throttle and it will turn off the motors, but what about holding down the throttle all the way when the P4 is 100 feet in the air? The motors don't cut out then. Yes, of course the aircraft knows its' altitude so it is smart enough to not stop the motors. But what about when you decide to catch the P4 out of the sky with your hands instead of landing it on the ground. In this situation the motors do shut off when you hold the throttle down for a few seconds.  How does it know you are actually doing a catch landing? I can certainly see a scenario where your holding down the throttle, the motors shutoff, and the P4 drops out of the sky from 7 feet.

Because it has to be still for three seconds before motors shut off. If it's not still it will be descending and the motors will not shut off.

Hello Healimonster, the drone keeps detecting its altitude in the air. If the altitude remains the same (i.e. landing on a platform) when you hold down throttle for few seconds, the motors will stop.But if it stops in the air, it is recommended to contact our service center for data analysis.

" I can certainly see a scenario where your holding down the throttle, the motors shutoff, and the P4 drops out of the sky from 7 feet."

It's a good thing that the Phantom designers are a lot smarter than all the people that imagine descending for three seconds will kill their motors in flight.