I wish it were true, but Americanism have been creeping into our English for years. The Senate finally stepped in a few years ago to clarify this issue: https://nationalpost.com/news/canada/the-debate-is-over-senate-of-canada-says-its-half-mast-not-half-staff-when-lowering-flags

But you can still find documents where CBC was confused on the issue: https://www.cbc.ca/news2/indepth/words/flagflap.html

The other one that drives me nuts is the insistence that only physicians can use the honorific of “doctor”. It’s actually become part of the Globe and Mail’s style guide.