No you are wrong. He had the training course. No adult required. And the gun was borrowed from friends in Wisconsin, not taken across state line. Also quite legal.
12-13 may possess firearm when accompanied by an adult, or while transporting cased/unloaded firearm to/from Hunter Safety class, or in Hunter Safety class. 14-16 is the same as 12-13, except Hunter Safety graduates can hunt and possess firearms (rifles/shotguns) without adult supervision.
Gun laws in Wisconsin - Wikipediaen.wikipedia.org › wiki › Gun_laws_in_Wisconsin
Her question was about pre-existing conditions. Very concerned about maintaining her donut-itis.