At 05:43:04, the Captain asked the First Officer to pitch up together and said that pitch is not enough.
At 05:43:11, about 32 seconds before the end of the recording, at approximately 13,4002 ft, two momentary manual electric trim inputs are recorded in the ANU direction. The stabilizer moved in the ANU direction from 2.1 units to 2.3 units.
This bit baffles me. Apart from the question of why didn't they get the aircraft back in trim earlier, at this point in time the situation looked just salvageable.
Presumably somewhere in-between these two time-stamps, the stab trim cutout switches were turned back on.
There is no mention of any cockpit discussion taking place from the CVR about turning them back on, so perhaps the Captain just reached down and reactivated the stab trim in desperation.
But why only two short blips of trim? They worked! It is stated the trim moved from 2.1 to 2.3 units. Re-engaging the stab trim was working! So why stop there? If only they'd trimmed it back to around 5 units and then hit the cutout switches again it would have become a manageable problem again. Surely every Max pilot in the world would have briefed themselves on this after Lion Air?
This makes the event seem all the more tragic - so close to solving the problem.