Ohio law allows you to cut the branches over your property line straight up to the sky...as long as it is not significantly detrimental to the health of the tree. Assuming it would be difficult to take more than 1/3 of the total branches off staying on his side of the line, it is probably going to be fine. Were they good pruning cuts? Common courtesy would suggest they talk with you first...but not a legal necessity. I won't prune a neighbor's tree without permission. Not that it is needed, but I don't need to go looking for trouble. If the two neighbor's can't get along, at least one is probably a loudmouth jerk and I don't need them disliking me!