i think that slander is a type of defamation isnt it? i.e. defamation includes slander and libel. I think it would be more likely to be libel if it was written on this blog because it is a permanent record rather than a transitionary statement which would make it slander. With any defamation case the burden of proof is on the defendant and a true statement cannot be defamation so id think youd get away with it, especially if the authorities had closed the shop down!