Like others, I suspect, I have been struggling to understand the PF’s reaction(s) after he was handed control of the aircraft when the AP dropped out.
I am not a pilot but my understanding is that the PF took action(s) opposite to or at variance with those normally expected in such a situation.
The apparent lack of meaningful/productive communication between PF and PNF – not going through SOPs, etc – and the frantic requests for the Captain to return suggests to me that in essence they had no idea what was going on or where to start to resolve things.
Accordingly the PF may have decided that everything he was seeing and hearing was incorrect leading to him shutting it all out as he sought to aviate. Using his ‘gut feeling’ his default position became an effort to secure altitude and power - to give a safe “breathing space” to evaluate what was in fact happening - thus explaining NU and TOGA.
I accept that PNF may have had some (growing?) understanding but he did not communicate this with the strength required or take over control apart from a very brief period before being usurped by a PF locked into a wrong belief about what was needed almost right to the very end.
As I say, I am not a pilot but wondered if the above explanation might fit with what tragically transpired…