Also, that all only applies to criminal statues, not civil/regulatory ones. If you're a construction firm who doesn't know that houses have to be built to fire code, maybe you'll escape criminal prosecution, but the government is going to take an axe to your business anyway.
Does that mean they have a duty to their own business partners or customers or investors to shut down their own business?
If we're looking for an analogy in this space, I think it's more like snake oil. So imagine a company started selling a new "nutritional supplement" or "herbal blend" that helped with anxiety. But it turned out the secret ingredient was weed. That would be a fraud on investors and they could well get charged for that on top of the base drug charges.
Courts never struggled with the legal definition of a sandwich. But yes, they had to come to a decision on what counted for legal reasons.
Please don't be so narrow sighted. Have you ever been charged with a crime you didn't know was a crime? You don't think overzealous sheriffs or prosecutors love pulling out old statutes on people?
Holding people accountable for laws they had no reasonable way of knowing is a miscarriage of justice. Our criminal system absolutely takes intent into account when determining criminality and sentencing.
I have no idea why people think the Howey test is so cut and dry when courts sometimes struggle with a legal definition for a sandwich.