I have a large Oak tree that has a large branch hanging over my neighbor's yard. These are large yards and it is nowhere near his house but does hang over some electrical lines going to his house. He got an estimate to have the branch removed as well as many other branches in other parts of his yard. He is a good neighbor, but has said he would help me pay for trimming in the past and has not followed through. Should I help him pay for this or is it totally on him? He did not ask me to. He did not specifically say how much that part would cost just that the total work he was having done was under $2,000. I always heard that any vegetation hanging into ones yard was their responsibility. Opinions?