Originally Posted by
ffsim
It was different last autumn when I was told, "sorry, sir, this bag comes from the US. You'll have to check it."
The catsa agent fully acknowledged that the bag was identical to the one used in Europe, but still wasn't allowed

Hopefully that's changed with the new rules in January, but I'll let you guess how much faith I have in CATSA's ability to consistently apply their own rules.
I still haven't done it yet myself, so I'm always looking for other people's experiences. In particular, I'm not sure if all US airport duty free outlets even use the proper tamperproof bag or not.