Great story. not that what happened to you is good but great detail.
I friend of my is a detective and he said that the vast majority of theft related stuff is BS, but they still have to look into it. The fact that the detective and not the cops showed up is really good. the fact that you got angry is GOOD. innocent people get angry when accused of something they didn't do.
quite frankly, the real estate business attracts a lot of unscrupulous and unsavory characters. don't take it personally. i'd bet that 1 in every 20 of us will run into the law at some point in our careers. most of it will be just a waste of our time.
although polygraphs are inadmissible, i think the detective wanted to see if he was wasting his time pursuing you. a friend of mine was accused of rape and he, like you, was absolutely furious and took a polygraph within a day. he showed the results to the detectives and very shortly after the charges were dropped.
as much as i'm sure you'd like to walk up to them and spit in their faces later this month, i'd advise professionalism. however, it might be a good deed to warn others that they fabricate stories about innocent people. maybe their accusations will dissuade others from working with them.
stick with it and best of luck. go make a ton of money and buy your daughters something nice. the looks on their faces will make it all worth it :)