How often could that happen? If you cut all the overhangning limbs even only an inch from the trunk, that's not going to hurt most trees. Any trees? Even that last inch, so the cut is flush with the trunk, would the loss of it hurt,
Yes, if the trunk has grown onto your property, you can't slice off a vertical segment of the trunk, but does anyone ever try to do that?
You have a point. Related, even if an old person is fully mentally competent, I think they atract con-men and no-good home repairers, with schemes that might as easily fool a young person, but because old people are targeted more, they may be victimized more. I have no data on this, but the female stockbroker certainly lied to my mother, and to me when I got involved.
(not that 72 is so old) And my mother was 85 and fully competent. Her next stockbroker commented on how well she knew her investments, their history, related laws, etc.
Back to the trees, I don't know about the OP's state, but wrt some issues, if the owner knows *OR should have known* that, for example, the limbs were sick and should have been cut off, he is likely responsible for the damage they do (I know there was no damage this time.) . I don't know what "should have known" means. Perhaps that if he'd just walked into his yard and looked up he would have seen that a limb has no leaves when other limbs do.