It's easy to get fooled. As a rule, the guys who are actually doing it right don't have a reason to be on the radio.
For what it's worth, the AV units have a 11 prefix (114, for example), and the Santa Clarita guys are 60's.
The discussion about keeping the rotarys on is so the chopper can maintain situational awareness. It's dark as hell out there, and easy to lose sight of where the horizon is.
The apparently casual manner in which they're constructing the perimeter is because they know that if the guy hasn't gone to ground they'll be able to see him coming for quite a while. They'll just get the place completely surrounded, then probably bring in the dogs and start working the hangers one by one. Nobody's going to rush into anything.