We're on the same page here. Section 351 isn't really an easy section to apply to someone who's just standing in the middle of an unlawful assembly with a mask on. That's the point we've agreed upon.
I want to ask you about something else, and that is mens rea. What I know about criminal law is that it is generally the case that to be convicted of a criminal offence, one requires some criminal intent.
Can you give me any citation for the proposition, which I think I've heard you and others provide, that it is possible to be convicted of being in an unlawful assembly with the court finding that you didn't know you were in an unlawful assembly and you weren't wilfully blind about it? Is there a citation that says you can be convicted for simply the act of being present in an unlawful assembly without any criminal intention associated with knowing you were in an unlawful assembly?