Reverse evidence
Do you have a damage claim and is the cause of the problem after research clear, but the damager of insurer won’t follow you? Then you can possibly propose to provide a reverce evidence. When they will not repay you for the damage, take the cause away.
If everything dries up then you possibly have a reserved evidence for the indirectly caused damage. Take the cause away and the damage disappears. You have to manage your own property with due diligence and limit the damage.
However, always have a written agreement drawn up in advance that the damager will take the damage upon himself after the resversed evidence. It’s definitely worth trying in a stalemate, before going to court.
A leak at the west side can cause condensational damage, mold and health problems at the colder east side of the house. A source can be on a different floor or even at the neighbors. By adsorbing moisture, higher vapor pressure and dew point condensation you get damage throughout the adjacent buildings.
Nobody can cause damage to others.