Don't see it Dev's. The plumber was asked to look at a bit of dodgy plumbing and tightened it up at the owners request which fixed it at the time. Plumbers have no physic ability to predict leaks of the future. A bit like your vehicle MOT it's all at the time of the test. i.e. If something breaks on the vehicle on the way back from the MOT garage that makes the vehicle not roadworthy you will have no recompense from the MOT tester because it was fine at the time of the testing. Got it now Dev's?