> These were _incredibly obvious_ duplicate entry errors when the Post Office investigated but they blindly took the system as perfect and automatically assumed criminality on the part of the postmaster

They did not blindly take the system as perfect, but instead they were well aware of the errors and instead decided to bully the sub postmasters and gain bonuses for successful prosecution. They knew exactly what they were doing and took pains to hide any evidence of the shortcomings of Horizon.