The officer did have RAS to contact you (although the information proved erroneous), which just goes to show that LEO often get's it wrong (or the 911 complainant got it wrong). As to taking your firearm, the courts have backed this up when RAS is present. However, refer to my first comment and the officer would of had no access to your firearm.
I really think you did fine other than opening the door too far and not returning his discussions with more and more questions. Why are you here? Who called? etc...
You did a great job by refusing entry.
It is your responsibility to assert your rights. It is the SCSO job to investigate the claims of the caller.