PPRT,
The A-26 was a non-aerobatic aircraft. Passengers were being carried in contravention of the regulations, some of who, I believe, were not strapped in and which may have been a contributory factor. Such flagrant disregard for the rules cannot be considered as indicative of a dormant problem with the existing operating framework of UK airshows.
About a month before that accident I was taxiing out to take off when the same pilot in the same aircraft did a departure flypast at another airshow with some bank applied and his wingtip was VERY low over my canopy; I genuinely did think that he was going to hit me.