If your car is yelling at you to grab the wheel, I'm sure you can take two seconds to put your phone in your pocket. With one hand even, so the other can go to your wheel, and your feet are still nice and snug on the pedals, ready to brake should you need to.
I think the crucial thing here is, in this case if you don't do any of that, Mercedes will still take responsibility for a crash until the ten seconds is up.
Therefore they need to be very confident in that ten second rule, and naturally we look for cases where it might not work out well.
