The sales person is supposed to do that anyway as part of the sales process....and even if they didn't all new cars come with what we like to call "the mystery book"..Its in the glove box and it explains all the features of the car, and how to operate them.
all that aside, I dont care how old or young you are, if your stupid enough to get locked inside your own car, you really do deserve to die there.
I have never had them explain that stuff to me, so I wouldn't say they are supposed to do that. I do agree with you about the stupid enough to get stuck in your car part
According to the article, the owners manual was inside the house, so they didn't have access to it. Not that they should even need to read the manual in order to know how to operate a standard automobile door handle.
That said there is nothing complex about the locks to start with so if they couldn't figure them out they must need the book.