Looping a civil Hercules at Farnborough?
 

Not a loop but a chandelle.

Well a wingover that included an inverted, wings level phase. :O

https://cimg7.ibsrv.net/gimg/www.gmf...b2575e22f9.jpg

Definitely very cool regardless. By not committing to a full loop I guess they can reduce the g loading on the entry and exit. Of course, the fact they don't show a loop on in the diagram doesn't they didn't actually fly one. The sequence of stills looks more like a loop than a wing-over / chandelle, but it's hard to know without being there in person.

As well as watching and approving each display sequence in advance during the week preceding the airshow, the Flying Control Committee, comprised of senior very experienced test pilots, watch every aircraft displaying VERY closely to make sure it sticks to the display which has been approved and any 'added' items will quickly be detected and the pilot admonished.
Each display is videoed so that they can play back what has been flown; they even analyse the positions of the individual control surfaces on the aircraft to decide whether or not the pilot is properly in control of the aircraft.

I don't think anyone is suggesting that the loop (or inverted wingover/chandelle, if you prefer) wasn't an approved part of the display routine.