Bigears,
I was worried about the rules and safety/security of the aircraft but that is less of a worry as we were on the ground and would be stupid for anyone to attempt a hijack on the ground would say something if it was open once taken off.
FlightDetent,
If the rules on UK airlines/aircraft are to not allow visits to the flight deck and only to allow them when aircraft has landed and all passengers have disembarked then the door should not be open at all while passengers are onboard.
Just my thoughts, everyone has their opinion.