Backpacker, you are very wrong my friend.
Sometimes it's almost as if the military in general (not just aviation) has a "get out of jail free" card and are able to pull stunts like this under the pretext of "training" without having to think about consequences for themselves or others. Maybe because as military, particularly foreign military, they are somewhat shielded from the normal retribution mechanisms of authorities like the CAA?
It may not be the CAA carrying out the 'retribution' but believe it or not the legality and authorisation of military flying is very strictly enforced. It is not unknown for aircrew to be interviewed under caution by the RAF Police (who are dead keen to press charges and court martial pilots) purely on the basis of a civilian flying complaint (although mostly radar tapes or GPS evidence later proves the complaint to be unfounded). It has the potential to be career killing stuff - not something the average MATZ intruder has to worry about.
Incidentally, in a fast jet environment, 500ft was possibly the worst place your friend could have put himself and was almost certainly nibbling his legal limits.