The reason why a pilot would only retard one thrust lever escapes me. Brainfart or not it has happened and may well happen again.
What I do find worth thinking about is why PNF did not recognise the fact, according to the CVR transcript. Assuming my understanding of the transcript is correct, he called "reverse number one only" as a reminder, then called "spoilers nothing". SOP is to call Spoilers then Reverse Green then Decel - so why no Reverse Green call?
Distraction because ground spoilers did not deploy?
Or disbelief that this could happen?
Or because his brain thought he had already called it?
Possible contributing factors:
With only 250 hours on type (IIRC) a Captain in the RHS on an occasional basis.. is he in his comfort zone?
When did he last fly a sector as PNF in RHS?
Was he distracted by the call to inhibit the G/S at 300ft.RA? And was this briefed, perhaps it is an "unofficial SOP'" on this runway?
Was he trained (and I mean trained not checked) to fly PNF RHS - RHS checks for Captains are done in the UK as PF. Perhaps PNF duties are just as critical?
If two Captains fly together should they stay in one seat for the duration of the duty? That's what Line Trainers do and they can still get caught out.
And why did PF not recognise the problem either? Many years ago I was given two golden rules.
1. If you move a switch or lever and all hell immediately breaks loose - move it back.
2. If you perform a sequence of actions and do not get the intended result - do them again correctly.
Rule 1 does not apply here, but Rule 2 might have helped.
Your thoughts welcome.
TP