A lot of people who aren't software developers have blind faith that software is always correct. Inversely, software developers never trust software to be correct.
Sure, and once the cases made it to court, I can see jurors taking the software evidence at face value.
In this case, somebody should have pumped the brakes well before criminal proceedings. But, it seems like the higher-ups didn't want to look bad, so buried evidence and charged anyways, which should be criminal (no idea if it is, I'm no expert in UK law).