This is still a bad example due to how state and federal law works. A better example would be me buying an old school steel jerry can from say Idaho and having it shipped to where I live here in California. Even though the sale of such jerry cans are illegal in California ownership isnt, and I didnt buy it from an instate vendor.
Also I dont know if old school steel jerry cans are illegal in Idaho I was just using it as an example, they are illegal to sell in California.