The door lock part of the story is easily falsifiable. Information about what type of locks his make/model/year of car he had at the time is easily verified by any competent auto repair shop.
And child safe locks only work on rear passenger doors. They don’t exist on front passenger doors because small children aren’t supposed to be sitting in the front.
Well this supposedly occurred in the late 1970s. And according to wikipedia: "Child safety locks are built into the rear doors of most cars to prevent rear seat passengers from opening the doors both during transit and while the vehicle is stationary; vehicles have been built with this feature since the early 1980s."
It’s also an issue of escaping a car in case of dire threat, fire, accident, and the like...