Unfortunately U.K. law does not apply to USA. It is a nice law though.
Unfortunately here in the USA we shit all over that idea.
Read on how USA altered time served rules after the fact.
Read how USA alter pedophile rules after the fact.
He just quoted the universal declaration of human rights, it's not a UK law, it's a general principle of universal law.
If what you say is true, I knew the USA was rubbish at some things, but this would take the biscuit. I imagine you have an exaggerated interpretation of the issue, because to be able to apply that without limit is not conceivable in a modern democracy.