Specific threats yes/ "I'm going to kill you Malcador". That will get you arrested. Generalized threats "I'm going to kill someone" not so much. It will get them looking at you, but until you actually DO something what can they do?
Haven't bothered to take a look but it seems like the threats were slightly specific from reports I heard. But yeah, they can't necessarily do anything worse than talk to him - that might put a scare on him but also might provoke him. Does seem like something one should lose their firearms for though, but I forget that's a right meant to have no restrictions down there