Now, back in the real world, the first thing police do when interviewing a witness or suspect is determine the identity of that person. It's really important for actually knowing whom it is you're talking to and also helps when follow up may be necessary. And lets remember, according to those filing the complaint, they knew who these two people were and likely informed the 911 operator of the names of the two people fornicating in public so the police were probably trying to ascertain if they were speaking with the right people. But hey, that wouldn't be important to you because you're an expert on police protocol.
Bottom line, for me, I'm prepared to concede that a police officer has far more knowledge about how to conduct a police investigation than some snide know-it-all spouting off on the internet.