The military air displays are commonly known for flying the envelope out so itīs not that strange that things goes wrong from time to time unfortunatly.
This comment reminded me that I have probably been to about 20 airshows in my life and seen rather a lot of "cock-ups", including the Fairford Migs, the Hurn F4's and, a long time ago, a Havard spinning in at a BoB display at St Athans.
My last trip to Farnborough was in the late 60's when the French Atlantique crashed. A contributary factor to this crash was the robust crosswind on the day and there were two further incidents which helped to make me even more twitchy. One was the Herald which burst a tyre on landing, and an Aeromachi jet trainer which struck the ground with a tip tank. You could almost see the pilot whistling nonchalantly as he hoped that noone would notice the fuel streaming from the tank as he taxied off.