With reference to hats and hi-viz jackets:
A colleague of mine ended up going off the end of a Boston runway at night in a DC-10 through absolutely no fault of his own. It was winter and it was snowing so as he came out of the flightdeck having completed the shutdown checks, he quickly donned his overcoat on the way out because it was bloody cold.
He then tried to get involved in the post-evacuation procedures but no one paid him any attention.
At one point, he was chucked into the back of an ambulance whilst trying to protest that he was the captain of the aircraft and was not hurt in the slightest. The enthusiastic ambulance crew assumed that he had received a head injury and was therefore not in a logical state of mind.
The problem was that he did not have his rank bars on his overcoat nor was he wearing a hi-viz jacket so, in the dark, once he put that coat on, no one could recognise that he was the captain.
Perhaps BA have learned a good lesson that some of the unpromising hysterics on this website have yet to learn.