My guess would be that the guy was confused in regard of the age of majority ... which is different in different provinces ....
Firearms are federal, so, of course it's 18 ..

The age of majority is 18 in six provinces: Alberta, Manitoba, Ontario, Prince Edward Island, Quebec, and Saskatchewan.
The age of majority is 19 in four provinces and the three territories: British Columbia, New Brunswick, Newfoundland, Northwest Territories, Nova Scotia, Nunavut, and Yukon