"as an ex police officer...."
what has that got to do with being aware of the difference between not guilty and guilty. In fact judging by your reference to "an innocent (cough) tax dodger" you appear not to know the difference.
"the legal system in the UK is not one to be proud of"
in my opinion, it is a damned sight better than many, many other places in the world
"and is stacked in favour of the guilty"
[?] I'm afraid I don't understand that. In this country nobody is guilty until proven so.