that he at least knew the repair he was making was not following procedure.
Valid, but then the question is: Was CO aware of that and happy for him to go ahead and do it anyway.
It wouldn't be the first time that an airline pushes its engineers or pilots to operate outside the regulation to cut corners only to point the fingers at them whenever investigators start gathering around the flaming wreck...
There is a reason the words 'pilot error' or 'human error' are always written somewhere on an investigation report. Blaming the employee clears the airline's management from any liability. All they get is a slap on the hand, maybe a small fine, and a recomendation to improve training.