I do know that the case is in California, not Arizona and the regards in question are held by San Bernardino County Sheriff's Office. Here's a rundown on California's laws:
Access to Public Records in California | Digital Media Law Project
Notice that preliminary materials can be held back in cases where the State is a party (as it would be in this case if it is a criminal case). Also that webpage says "Law Enforcement" documents in general.

However, search warrants would be public.
Search warrants, if served in Arizona, have to be filed in Arizona, I believe. Which is one thing that worries me. It's expensive/time consuming enough to do things in one's own state/county but at least SBSCO's main office is in the same place as the Court. I have no idea what sort of thing they have to do to get a search warrant in AZ, if they ever decide to seek one. And if they did seek one, we on WS don't know about it. I wonder if that would fall under Arizona's privacy clause?
He never mentions an earlier stop and in absence of mentioning that and in the presence of him using pictures from the Kelbaker hike to show police they were there,
and the fact that RT says they can see a parking lot with cars in it nearby to where Barbara went missing from the top of the hill and wants LE to check out those license plate numbers it's unreasonable to assume they went to some other place and some other hill. Even if they did, RT says they saw a parking lot with cars near to where Barbara went missing. From a hill. While they were hiking. It makes no sense for RT to point to a hill miles away and a parking lot miles away, IMO.
Also note that the SAR team climbed the boulder pile/hill and posted pictures of themselves on top of it. We have puzzled over which "parking lot" was visible (and we don't exactly which pile of rocks, either, there are two candidates), but the main pile of rocks/hill would have had a view of the turn-out just north of where the RV was parked. WSers who went out there say that the southern turn-out would not be visible from that hill.