My answer depends on how one understands it. Based on the interpretation that's being put forward by some members of the committee and the other witness, I think it's constitutionally problematic on a number of fronts. It could run afoul of the prohibition on reverse onus, which is I think what the Canadian Bar Association is getting at in respect of proving a lawful excuse. But I also worry that it could run afoul of the right to freedom of expression and freedom of peaceful assembly. It could be interpreted as allowing for preventative arrest of people who have not engaged in riotous conduct, who have not actively engaged in acts designed to disturb the peace in a violent way, or in a way that's designed to occasion property damage.
I have no difficulty in criminalizing that kind of conduct, but it already is a crime. Subsection 351(2) makes that a crime. If a rioter puts on a mask to conceal his identity so he can perpetuate the riot, he's guilty of participating in a riot as well as wearing a disguise to commit an indictable offence. This proposed provision doesn't add anything to that. It just creates room for uncertainty that ensnares potentially innocent law-abiding protesters. As a result, I think it is susceptible to constitutional challenge for the reversal of the burden, as was identified by the Canadian Bar Association.
But I have to say I'm more troubled by how it's being understood by the people in the room. Frankly, I don't understand the desire to add this provision to the Criminal Code. I haven't heard anything from anyone that tells me why subsection 351(2) doesn't do the job. This provision will be read to include an intention requirement. You can't get around that. And if you try, the court will invalidate it as violative of the charter. You have to have a minimum mens rea requirement. Section 7 of the charter demands it, and the Supreme Court said as much in 1985 in the motor vehicle reference.
I hope I've answered your question.