Just out of curiosity what are the written down (RAF) rules regarding taking cameras into the cockpit (whether it be ME, RE or FJ)?
Not sure there were, I certainly can't recall any from my time on (ME) types. Rather, it was left to 'airmanship' to determine that which elevated risk.
Pretty sure some rules will be following shortly, which as usual will be of the lowest common denominator variety, affecting those, the vast majority, who are sensible, as well as the numpties*.
*That's probably a little harsh, I've witnessed a very experienced, reliable, capable and trustworthy pilot have a 'momentary lapse' and bust a descent altitude because he was taking a photograph during an arrival procedure.