> How much risk was there of some harm coming to the child while the parents were gone?
As a parent to young children, I would say pretty damn high, actually. Kids do stupid things all the time, and if you aren't there, and they know you aren't there, there is no limit to the stupid things a 2 year old can do. It's a normal part of growing up, but that doesn't make it safe to do it alone in the slightest.
That said, I agree with the gist of the article overall.