Well they are probably locked behind cabinets like in Michael Hill, but you have to take them out at some point.
It seems another person was found critically injured at the Gun City. I have serious questions around how they haven't been found until now but I'm sure answers will come in time. Article here: https://www.rnz.co.nz/news/crime-and-justice/1002408/another-person-found-wounded-at-gun-city-shop-where-man-fatally-shot-by-police-took-gun
There's a photo of the front of the shop there. It doesn't seem any more secure than PB Tech.