The location of the Paragliding site which the Hawk overflew at low level is clearly marked on the 1:5000,000 chart, but apparently from the AirProx Board discussion not briefed or considered. The Hawk pilot apparently believed he was inside the danger area at all the relevant time, and that does have a bearing on his situational awareness, as provided by the pathetic (in current technology) display.
I do understand Military Procurement budgets, Timetables and constraints, and the problems of operating fast jets in the geographically limited Salisbury Plain operational area.