During periods of extreme stress...human memory can be a poor tool when looking back at a sequence of events as one focuses upon the most immediate issues of concern while missing most of what else is going on at the time.
Nothing unusual about that at all.
As good as the Pilot accounts shall be....they do not necessarily tell the whole and entire truth of the event. Not that they are being intentionally deceitful....not at all....just that they were deluged with inputs, sounds, lights, physical forces, and as is common in very serious emergency situations....took actions that were a result of training and experience that they may not even recall having done.
The CVR and Data Recorder does not suffer from those Human weaknesses....the wee digital memory they use retains everything without any emotion or psychological constraints. They too have their weaknesses but when combined with all of the evidence the AAIB shall discover.....the Truth of this tragedy will very likely be found.
The CVR and Data Recorder are crucial to a successful investigation as they do hold an incredible amount of information that is so useful to the investigators.
An example.....during Simulator Training I used to videotape every single Sim Session. Sometimes I would take the Trainees down to the classroom...get them Coffee....turn the Video of the Previous Session on for them to view while drinking their Coffee.....and when i returned....you could see a much changed demeanor in them as they got to watch their own performance....or lack of in the Sim earlier.
It was not unusual for them to admit they were no aware of some of the things they saw in the video.