https://wisconsindot.gov/Pages/dmv/teen-driver/yr-frst-lcns/... https://wisconsindot.gov/Pages/dmv/teen-driver/yr-frst-lcns/...
If Jason Davis was driving under an instruction permit, he did not have anyone in the car to legally supervise him under Wisconsin law. If he was driving under a probationary license there was a possibility he was driving legally if he was past the 9 month requirement without it being extended, but if he was still in the initial 9 month period he had more passengers in the car than he was legally allowed to have. It is possible for him to have been outside the probationary period of the probationary drivers license, but that would require him to get his license some time between Jan and March of 2016 and then immediately get his probationary 6 months after that with all the requirements entailed, and I find that unlikely.
This seems to me to be a series of bad decisions made both by the teenager behind the wheel, and the parents for letting him do so.