Of course it matters who is responsible, would you cut your neighbours grass because it has overgrown?I don’t think it does, because if you were paying attention you’d notice it needed doing and do something about it, whether that something was doing it yourself or ringing the council and telling them to get their finger out.
I don't think the Allams would take a walk down there to check that its been trimmed back and the walkway hasn't started to break up.

