For what reason is their measuring frame, that is, their wooden corner, actually standing so far on your property? Or is that just an illusion caused by the perspective? Your downpipe is also nicely exposed and is not supported on the KG pipe, and the studded membrane above the insulation is only there as an alibi. I fear that you will need quite a few discussions before the original condition is properly restored. Or have you already planned to have the reconstruction monitored on your side?
In any case, I wish you that the neighbor comes to their senses and that you can live there peacefully in the future.