I have always been slightly irritated by the claims of credit and copyright by individuals for photographs which were only taken with the contribution of several or many other people. For instance, the 56 Sqn Lightning photograph required the cooperation of each pilot in the formation and the efforts of the groundcrew to prepare the aircraft and other essential aircraft operational support functions to be undertaken. Why is credit not given to them too.
I understand that the Gnat mishap photograph may not fall precisely into that category, but I expect that, for it to have been taken so close to the aircraft, the photographer was paid to be there to record the events for the subsequent inquiry. In which case, the copyright should lie with the crown.