As you probably know, I was a technical advisor to one of the legal teams at the FAI. As such I framed questions, and instigated supplementary inquiries to various agencies, including the AAIB, in preparation for the (then) upcoming FAI. A very lonely time I might add!!
I had further correspondence with the AAIB, asking supplementary questions requiring further wreckage examination. For example I requested further analysis to determine whether the forward cabin upper door was open or closed at impact. This could have been significant, but had been overlooked initially.
My memory may well be inaccurate, however I recollect having a discussion with the Senior Investigator of Air Accidents, the very impressive Mr Tony Cable whilst standing in a very depressing hangar at Farnboro. I thought he said the position of the switch was not necessarily reliable as the sequence of severe multiple impacts may have affected it.
I am away from my documents for a little while, but there is a section in the AAIB report which allocates a confidence level to all cockpit indications recovered from ZD576. Isn't this switch included in that list??