That's questionable

I work at a major chain bookstore in Hollywood. Tonight a guy wanted to return a book without having a receipt. We have a clear policy on the matter, if we don't carry the title, we don't take it back. He didn't like that answer. After talking with one manager, it came to me to verify that the other manager wasn't wrong. I concurred, we won't take it back. He got real condescending after that. He said, and I quote 'Is there any OTHER manager I can talk to at the store right now?' I replied, 'No.' He rolls his eyes and said 'So, you two are running the store right now? Just you two?' I replied, 'Yes.' He then says, 'Wow, you two running this store, wow, that's something else...that's just, wow, that's questionable.'