That is one way of Disconnecting the A/THR in the situations you described, another is to set the required thrust, or match the lever position to the current thrust setting and then press one of the "Instinctive Disconnect Buttons" located on the Thrust levers.
On the B787, and I believe other Boeings, you have the ability to retard the Thrust Levers during any phase of flight, the Thrust mode goes to HOLD, and the thrust delivered will be matched to the lever position, then you reset the levers to the commanded thrust, and the A/T takes over again. It is common practice to have to do this on descent as the aircraft will struggle with the VNAV Path as it sets a higher thrust than it needs for the descent.
Coming from the Airbus it was a bit weird, but you get used to it and can be useful in certain situations.