Joseph there are problems with that theory. But it does not benefit anyone to point them out. I also don’t know why it’s important to make up stories about how the baby was left in the car when the others weren’t. Anyone with kids knows that older kids don’t like to sit in the car while anyone with babies knows the temptation of leaving a sleeping baby lie.
Although I never understood it I know many people who left their babies or kids in the car thinking they are “just running in and out”. When they get in, with empty hands, they can get distracted and forget they were in a rush. That can happen and is much easier to believe than many of the above stories.
I’ve even had ‘friends’ who ran to carpool while their baby slept. People get desperate when they are stretched thin.
I am not excusing or even understanding the behavior but it’s not that uncommon. We can pretend it doesn’t happen but we wouldn’t be doing anyone any favors.