People were walking into non-restricted areas of the military bases that were open to the public. None of the incidents discussed in the article were in restricted areas of the bases. That's not to say they didn't fall under the security of the base, so it would be reasonable for the commissionaires tasked with base security to investigate suspicious activity even in non-restricted areas.

E.g. Fort Fontenac, one of the bases named, is the site of a historic battle and so has cultural interest open to the public. But it also has official Canadian Forces business conducted on site. Similarly some of the CFBs have museums etc and are generally open to the public.