FO under training for the left hand seat had a brain melt and stuffed the nose forward at low level. Not saying this is the case, but can’t be ruled out....
Nice to have the AAIB on board, especially with such insight. But did you consider the possibility that all the passengers, seeing the problems the crew were having with gusts, decided to rush forward and advise them how to handle it? Not saying this is the case, but can’t be ruled out....