Maturity doesn't have a whole lot to do with this, in my opinion. As parents we teach our children not to talk to or open the door to strangers, UNLESS it is a police officer or fire fighter. This kid simply did what he was taught and since he was in the car I see no way he could have known the guy was intoxicated. Maybe the mom shouldn't have gone into walmart but that is far from the point here and far from who fingers should be pointed at.
If I am leaving a 7 year old and a 4 year old in someone's care, then maturity matters a lot to me. There are 17 year olds I would be afraid to leave them with, and yet, there have been a couple of 13 year olds I would be fine leaving them with.
If I'm leaving young kids with someone, I want them to have the judgment to be able to make decisions by something other than very simplistic "Do as a firefighter tells you." I have also read "Protecting the Gift" by Gavin de Becker, and I would never tell children not to talk to strangers. Far better to tell them not to *go anywhere* with someone other than the adult in charge.
I find it really scary that the 13 year old would be willing to take the two younger kids and go with the guy into Walmart.
I also find it completely irresponsible for the mother to be leaving her kids in a car on a summer day in a Walmart (or other big box store) parking lot on a summer day. If the car wasn't running, the heat could be an issue, if it was running, one of the kids putting into gear could be an issue.
Ultimately, the kids were safe, which one could argue meant that the 13 year old was competent enough, but honestly, this could have gone wrong in so many ways that I think the mom was negligent.
