We are one of the only countries to practice forced adoption
That isn't correct, a huge number of countries have adoption without parental consent. It's more uncommon for a country not to do it.
The reasons we don't like JH have been gone over and over and over on scores of threads over the years. It comes down to the fact that whilst everyone acknowledges some reform is needed, Hemming has spread conspiracy theories, aligned himself with complete nutacses like Ian Josephs, never has evidence to back up his conspiracy claims, and goes about trying to get reform in the wrong way
I am glad to live in a country where children who have had the most appalling starts in life can be adopted and be able to be a part of a proper caring family. The idea that children like my adopted children should live their whole childhoods in care and never have a proper family is frightening and very upsetting
But I was wondering what would happen if years down the line it was proved that the parents didn't harm their child?
Has it ever happened?
Obviously te adoption would stand as you can't rip the poor child from another mummy and daddy but would the birth parents regain rights?
I'm not sure there's ever been a case where it has been proved beyond all doubt, but I'm not 100%. There have been cases which are likely to be miscarriages of justice but nothing proved because the evidence has never been tested and a court made a conclusion
If it ever did happen, then no, the birth parents can't regain rights in the sense of 'reverse the adoption'. There is a small time period after an adoption order is made to appeal it on very limited grounds (that the correct legal procedures were not followed) but after that, the effect of adoption is that the child has, in a legal sense, been re-born to their adoptive parents. It is 'as if' they gave birth to the child. The birth parents are not related to the child any more. There's no legal way to reverse that in law and have the birth parents regarded as 'the mother and father'
That said, lets suppose it was determined that it was in a hypothetical childs best interests to share custody with their adoptive and birth parents. I don't think there's any legal reason why if the adoptive parents consented, the birth parents couldn't get one of the orders that step parents usually get, which gives you parental responsibility until the child becomes (it is an adult, or 16?). But when the child becomes an adult, the birth parents would stop having responsibilities and wouldn't be regarded as being related to the child, except for laws on incest/marriage etc