Given the fact that someone retracted the droops 63 knots and 1300 feet below prescribed limits, and four trained men could not understand the resultant stall warning, I'd say any amount of confusion - during the 'event' or the investigation - is possible.
Following any accident, an aircraft's entire technical records are quarantined and made available to the accident investigators.
Since an important part of any investigation is to explore the possibility of precursor technical issues as a causal factor, it's frankly insulting to any investigation bureau (the UK AAIB in this case) to suggest that it's "possible" that they didn't bother to look at the aircraft's paperwork.