I didn't mention it in the comment you replied to, but during this whole event including the 4 instances of police, Ben is in a car with a process server he hired to serve the papers. Ben himself stayed on public property the whole time.

The cops even tell Ben to get a process server, and he points out to the cops that yes, he has brought the exact person they described, she's right there in the car with him.

I can't speak for Utah, but I sued a valet for crashing my car in small claims. I was given the option for an additional fee to have the subpoena served by the Los Angeles Sheriffs Department. I think you're better off getting police involved if you can when it comes to serving people. In the case of the video I'm pretty sure he hired a certified process server and the police shut it down.