David49 I find legal tax avoidance, in many cases, to be fairly tacky and unpalatable (and is especially so when a person presents himself as a patriotic and principled man of the people). I do have a little experience of legal tax loopholes, having worked for a very successful central London firm of tax lawyers, where I was pretty shocked to see the sorts of shenanigans that were recommended by lawyers to their wealthy clients seeking to legally sidestep paying taxes.
However, I think there are no excuses to be made for deliberate tax evasion and, in theory, such actions should be litigated.
My quote was that HMRC has not charged a single company under landmark legislation passed six years ago to crack down on corporate tax evasion.
Rich people and corporations can afford to employ the most skilled tax lawyers to run rings round understaffed and possibly less able government employees. I have read that the tax authorities try to assess which cases they are likely to win, and therefore litigated, and which cases should be settled in a civil setting through "compromise". It would appear that either no proper investigations have been made or that the imbalance in resources has meant that reduced payments are accepted rather than suspected wrongdoing being litigated.