The subject passed multiple cars running sirens within the first minute or so after leaving the first scene. I'd wager those were police, so I'd bank on the near miss prospect at the first scene. What's unknown is what their purpose was.....Wikipedia actually has a
pretty good description of how police are armed in NZ. Apparently they don't routinely carry their Glock 17, but "the majority" wear a holster attachment on their gear (something similar to a Safariland QLS, I'm guessing) and don the holstered Glock from their trunk if needed. In addition, "the majority" have patrol rifles in their trunks.
Who knows whether it could really be considered a near miss, though. It could've been unarmed cops who were closest and only arriving to setup the outer cordon to direct traffic away from the scene.
Another thing to consider is that right of bang, there's still "dwell time" before emergency services can get going due to what is essentially the OODA loop of the people on scene. If you watch dash cams in the US, it's readily apparent that witnesses usually debate for a minute or two before calling 911. In active shooter incidents in the US, many people in the targeted building usually hesitate to leave. People are trained into inaction, and try to rationalize what they see/smell/hear in sentinel events as something normal. "At first, I thought it was a nail-gun" being a common one for survivors of active shooters. I'm going to danger that this situation for bystanders was no different, given people were still loitering around the immediate area.
It's one of the reasons that the US Dept of State's 1 week high threat orientation course for foreign service officers covers not just tac-med and driving, but also an afternoon session of literally listening to someone shoot various types of guns, the goal being they can identify and act instead of hesitating.