He wouldn't have a leg to stand on in court. In fact, from what it sound like, you would actually have the better case.Thanks, I had the same thought process and even offered someone else's skills to do a sanding job, but the customer was not happy with a sanding solution. The customer wants to have the floor re-tiled which I have told him is ridiculous.
After a few weeks elapsed the customer has sent me a letter saying i had the opportunity to rectify the job and now wants to put in a claim against me for re-tiling the whole floor!!!
If you suggest a fix, and the customer doesn't accept, it's their fault the floor is still like it is in some sense. To rip the floor up and re-tile it which could end up with even more lippage isn't the best solution for either side of the argument.
I'd say to him "I'm coming monday to fix the floor" and then just turn up and do it.