Tigs2: yes, it could be quite entertaining in a downwind posture! Hopefully, the wind was always at the forefront of 'the plan' for the display!
Crab and oldbeefer: now, there is a story! Did you hear about the certificate that was awarded a few years down the line to certify that wing-overs were flown safely by a certain party?
As for the ploughing - I would imagine the machine would have been around 12 tons for the display so any soft ground would have been assaulted in style. It if had just sunk, I suspect all would have been well, but the whole aircraft rotated around the nose wheel to the point where the rear gear was well off the ground. The forces on the oleo would have been very high.