Is it possible that
the German guy was wearing lederhosen or that he could
have been blown over by the jet?
I'm not sure about the first question, but there are a number of 'spotters' who will attest to the latter being possible - RIAT 01 (I think) was the last of 2 yrs that the show was held at RAF Cottesmore. The 'ladder' guys by the fence in the farmer's field by the active runway's threshold were blown off (!) by and felt the heat of the departing B1B !! I think there were a few minor cuts etc ?
Also, to add another much viewed YouTube link ...
http://www.youtube.com/watch?v=AjGdJN1_8u4