The cops need more than curiosity to get your name and dob. Once the weapon was checked and found to be empty, the cop had no legal authority to demand a name, etc. There is nothing that prevents the cops from asking, but like this officer did, if you get a negative response you just call it good and walk away.
In the opening seconds of the video, the officer stated that he got a lot of calls about citizen walking down highway. After asking about the gun and if it was an "Airsoft", which citizen said it wasn't, he says "Is it loaded? I'm going to check it for MY safety before we go any further, ok?" That certainly doesn't sound like a "confiscation" to me like someone else implied
With that being said, if any finger pointing is to be done, it's at the folks who called the cops, Officer Lyon was just doing his job in responding to those calls...and a damn good one too.