Common asbestos fence is cracking - how to deal with neighbour?

Hi everyone

I have a common asbestos fence with a neighbour who has previously been very very unreasonable and difficult to deal with.

There is a hole with a crack in the fence.he has patched this over with a piece of sheer metal on his side.

Is he obligated to pay for half of the fence replacement given it is damaged?

How should I approach it?

TIA