Various shortcomings have been discovered during the course of the AAIB investigation concerning safety procedures, but even if these had all been correctly followed, it would not have altered the outcome of this specific incident.
How can you be sure of that?
Page 25 of the Shoreham Special Bulletin (Link below) states:
"In 2014 a display by the pilot of G-BXFI, in another aircraft type and at a different venue, was stopped by the FDD of that display following concerns about the execution of a maneuver.
A CAA Flight Standards Officer (FSO) was present but did not witness the occurrence.
Following an informal discussion with the pilot later that day the CAA took no further action and did not formally record the occurrence.
The occurrence was not otherwise investigated and was not reported to the AAIB.
It may not have been apparent to those involved that the duty to report could apply to such occurrences at flying displays or they may have concluded that this occurrence was not reportable.
Nevertheless, the occurrence could have provided an opportunity to explore the pilot’s continued competence"
https://assets.publishing.service.go...016_G-BXFI.pdf
The CAA do not have to "witness" any event to take action. Notwithstanding, a YouTube video is available of the display:
https://www.youtube.com/watch?v=ZHngQ8TmqU4
Revocation/suspension of display permit pending assessment, or at minimum, an official letter of warning/caution may have indeed prevented the Shoreham tragedy.
The CAA had the first opportunity to take preventative action, but failed in its duty of care and duty of competence.