Uh, I don't think they were referencing the guns.
"The vehicle also had flashing emergency headlights, a siren and a public address system, the Patrol said"
And I don't disagree the reporting sucks. Were I the reporter, I'd certainly have asked him where the hell he was going with all that stuff. I'd also have asked whether there was ANY ammunition in the car. There's one gun bag there with ammo pockets, but no visible ammunition.
When I was in the military we were allowed to open the base range during certain hours if we took the class and adhered to all the rules. It wasn't abnormal for my entire shop to show up with a combined arsenal that could shame a third world army.
As far as being paranoid, anyone worth their salt doesn't carry multiple weapons that each have different ammunition requirements. From what I saw there were only 2 weapons there that could use the same ammo.