All I can say is that at the motorway end, I missed the accident, and was suddenly aware that all four fire engines and an ambulance at that fire point had started up, blue lights etc., and gone haring down the taxi-way at high speed. I think that, for the purposes of accidents/incidents, that the airfield and it's surroundings are divided into sectors, and an accident in a certain sector is the resposibility of the fire crews nearest to that sector, together with back up from others if need be. I have been attending shows at Duxford for many years, and have witnessed several accidents/incidents, and the response of fire crews has always been instant. [Unlike Oshkosh, in the States where response has always been dire compared to the U.K.]
With respect to one of the posters, I was unfortunate enough to witness a crash at Mildenhall, on the airfield, and on the news on ITV that evening, a witness complained that it had taken the first emergency vehicle six minutes to reach the scene. I replayed my video, and timed it , and it turned out to be 1minute 30 secs. In instances like this, time does seem to stand still, and a minute can seem to be a very long time indeed.