Vent pipe connection to soil pipe

[Taylor9898]

Following the recent installation of a bathroom, I had a leak causing damage in the room below caused by a partially decoupled vent pipe connection to the soil stack. It was likely unsettled by the installation. My insurance company have refused the claim on the grounds that the flexi bend connection is 'defective', a substandard fitting to the soil stack. The connection has been there since at least 1993 with no issue. I would appreciate expert option as to whether a flexi pipe connection to attach the vent pipe is acceptable? The vent pipe comes through the roof and is connected to the soil pipe with an angled flexi bend. Many thanks in advance

 

[Taylor9898]

I have attached photo