I am sorry to have to tell you this of these are your trees which you agreed the neighbour could cut down, then the trees belong to you. In fact, if he took the branches and the trunks and soul them, that would be theft.
Of course, if you agreed that he could keep the trees, then it would not be theft.
With regard to the roots, this is trespass from your land onto his land and if the route do damage his property, but I am afraid that you are liable in negligence. He is entitled to prune any trespass, route or overhanging branches which go onto his land but he must not destabilise their kill the tree.
I’m sorry, I know the answer is unfavourable but the law is quite specific, the trees do belong to you and there is no onus on him to remove them. It would have been different if you had agreed that in exchange for him cutting them down, he would remove the debris.
Can I clarify anything for you?
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