One common item seen in the simulator is where on a high sped rejected take off, the pilot first presses the auto-throttle disconnect switch (in the end of each thrust lever on the 737) then closes the thrust levers. That loses one second or more before the action of closing the thrust levers. End result is 250 feet of extra runway required to pull up
The disconnecting of A/T and closing thrust levers are to be done simutianously,obviously the finger disconnecting the AT is a quicker movement than of retarding your arm to close the thrust lever.
You may see this as an issue,i dont.
At those high speeds, the disengaging of the autothrottle does nothing as by then it is already in throttle hold
It is a procedure to follow as not to have the auto thrust quicking back in after the thrust lever has been closed,low or high speed,it is to be performed the same way.