All barristers are only as good as the evidence given to them

That’s not entirely true. The Secret Barrister made a good point on the site I won’t visit to grab the link: people always ask how you can defend someone you know is guilty; they never ask how you can prosecute someone who you know is innocent.

We have an adversarial system, not an inquisatorial one. Barristers are paid to present one case or the other, not decide what is true for themselves.

There are barristers and judges who may well be sanctioned, professionally if not also criminally, for their part in this scandal. Richard Morgan is one that sticks in my mind. He relied on an entirely circular argument (Lee Castleton signed off the accounts therefore the reliability of Horizon is irrelevant, even though it produced the accounts that Castleton had to sign if he wanted to continue trading). If you read/watch his appearance at the inquiry, it appears to literally dawn on him during the questioning. He was professionally negligent and he should not be allowed to get away with it.