Exactly, People are confusing what the helmet manufaturer's tag states and what the LAW in ONTARIO states. Manufacturers build things to conform to the widest possible market. Just as Radar Detector manufacturers don't put on a label that says "this is illegal in Ontario" instead they say check with your local laws, to CYA their butts.
The reg states a helmet can NOT have anything ATTACHED, to the helmet which protrudes more than 5 mm, This would include the "mohawks", "spikes" "cameras", (not limited to GoPro). Technically, the mount is attached regardless if you use crazy glue, tape, etc. That is why communicators ARE permitted as they "clamp" to the side of the helmet and as such sit "adjacent to" the outer shell they are NOT attached to it.
I get it, people think this is a silly regulation. I don't know the reasoning behind it, but assume it was likely that a manufacturer, (likely for liability reasons with lawyers involved), said they "couldn't certify the safety of the helmet" with something attached to it. So some bureaucrat wrote the reg. Trying to come up with a "creative" way to try to beat the charge, "may" end up pissing of the JP. The courts have ruled, (the rulings stand for now, until someone spends the tens of thousands on an appeal).
Therefore why paint a target on your back, (especially in the Kawartha Lakes, where they seem to have a hard on for this charge)? Just remove the camera, and mount it elsewhere. Having a camera mounted ON your helmet is not a safety issue, which is going to prevent or save you during a crash. mount it to your bike. Sure, some of you might think you get a "better view" from the top of your head. But if your truly using it for the sake of security in the event of a crash, then the best view you can have is from the bike looking forward, where the vast majority of bike collisions occur. Just not worth the hassle to me.