Are sure it was an RN Lynx?
I saw a set of 5 (3 of them pretty horrible, very graphic) pictures recently that sound similar, only these were of a US Seahawk (H-60), could they be the same ones? The time in the bottom right of the picture was around 9:44am.
It could be that a gust of wind caused a blade to flap during shutdown/startup (without the droop stops in), and he was unfortunate enough to be under the disk.
It's one answer to the question "Why do people duck when going to/from helicopters" that people seem to ask me.
Somebody where I work didn't believe that the rotors could go that low at the front, then I showed her the great bit of video of the helo (CH-53?) chopping it's own refueling probe off while chasing the drogue.