The cops just made the threat because they're annoyed, most beat cops would recognize the run time is literally less than 10 days by that point and realize the paperwork isn't worth it and its even noted in the report that the filming was due to be over. The "disorderly house/business" threat in the paperwork is just a "Cover your own ass" memo by the cop if it somehow became a bigger issue later on. When dealing with reporting stuff you always have to keep in mind how it will be interpreted when shit hits the fan and the cop is doing that for his own safety.
You think Sam or any of the wiggers thought that? You think, even if they
did consider that a possibility, they'd take the chance and risk what could be effectively a swatting that kills the show? As far as they were concerned at the time, and as far as
any reasonable person would be concerned in that situation as it was happening, one more call = cops come up and shut everything down. What's the solution to that? Screech at your viewers to "DON'T. CALL. ANYBODY?" Pinkie promise the cops there won't be any more problems, honest, and hope for the best? That's too risky, they had no way of knowing whether or not another call from some retarded fan, or Brandon, would come. They judged the risk of staying there too high based on the information they had at the time.
It's easy to look at it in hindsight and talk about what you totally would have done if you were not only in their shoes but also had all the outside-the-show knowledge and distance you have now, but at the time staying in the house was, as far as
anyone reasonable could assume, a gamble at best. IMO they should have just ended the show early, as awful as the RV trip was, but at the same time there is a sunk cost fallacy and a "show must go on" mentality that most if not all of production surely had at that point, and that's why they did the RV trip. If only they could read minds and know the cops were just wagging their fingers at them (which nobody knows even to this day, it's just assumptions), but they couldn't.
Funnily enough, ALL of this could have been avoided if only they had properly pre-screened Brandon instead of seeing a campy gay guy for 10 seconds, thinking that was funny, hitting the galaxy gas and flying him in.