It is the job of the AAIB to investigate an air accident, not to assign or apportion blame.
Information or evidence of previous incidents may only be included if it is directly relevant to the accident under investigation. So previous breaches of display flying limits may be considered by criminal investgators when deciding to mount a prosecution, but not by the accident investigators for this specific incident. Had the aircraft suffered unrepaired damage as a result of some previous incident, then that would be relevant and included in the investigation to be eliminated or implicated as a possible cause.
The pilot's experience, actions and liability need to be assessed seperately unless there is prima facie evidence that this is a direct cause of the accident. It is interesting to note that all AAIB reports take considerable pains to anonymise the identity of pilots and crew involved, even if the full details are already published and in the public domain.
One of the areas addressed in the report was what degree of sanctions were applied to display pilots who breached the safety rules. It seems that a quiet word in the bar or via telephone after the display was concluded was deemed sufficient in most cases.