Originally Posted by Man Flex
The PF didn't apply the appropriate procedure which was "THR LVR... MOVE" he instead disconnected using the disconnect push-buttons and because the thrust levers were in the climb detent the thrust increased immediately to climb thrust.
I would think he did MOVE the THR LVRs, fast enough that it's not showing on the thrust lever FDR trace. A quick move out of the CLB detent and back into it.
Using the disconnect push-buttons would not do anything as A/THR is already disconnected.