Plumbing issues, probably over 50K damages + Help please, whose responsible, insurance/plumber or me

I still dont understand how a internal plumbing leak for a shower involves a flexible braided hose. They are only even used in visible / accessable situations for ease of service and detection of defects. Not inside walls.

And how do tiles crack from a leakk / drip ?

I wouldt tell the insurer that. This means there was a defect first. The water leak didnt CAUSE any damage. It worsened it. Uninsured.

 

Google plumbing pressure test......

The practicle idea is that the plumber pressure tests the "house", this is done by (As you stated earlier) over pressuring the plumbing system to see if it holds that pressure for a set period without the pressure dropping.

Clearly the flexible hose held the pressure for the req'd time (As did everything else) and the system passed or they would have investigated further.

Just because a tap drips or a hose leaks a day or week later isn't necessarily any one's fault.

You can do nothing until the insurer gets back to your mother (Not sure why you are stressed anyway, it's clearly not your house for a reason).