Response from Dave:
You are right that we should have just walked out! I didnt understand how airbnb works properly... well I know now and anyway, airbnb provided my money back thank you very much! it seems like we were just unlucky that this time maybe you were too stressed about the leak to clean properly (just bad luck for us, I am sure other people have been more lucky thats why they gave better reviews!). I think when something really bad like that happens actually you should call airbnb and get them to find other accomodation for your guests. If it isnt luxury you shouldnt be taking their money!!! anyway, i wish you the best!