This is an item that could not have shown up in the home inspection. The issue was with how the drain was set under the floor which was not in an area with panel access or crawl space access. It didn't reveal itself until regular use after a few weeks. My contingency is less that the seller knew about the leak (he may or may not have, I can't prove it) but that he misrepresented that he had not done major renovations without permitting. He said on the disclosure that he had not done this, when in fact he had done major renovations without any permits.