I have kids, and to say it "could happen to anybody" is a far overreaching statement to make.
It might happen to parents with a pre-existing mental health condition, or drug problems, or a parent who was the victim of a stroke ... but for any parent I've ever met, forgetfully leaving their child in a car for 8 hours would be fundamentally impossible.
When my daughter was a child, I was aware of her location and well being 24/7/365 for years and years on end. The same is true for every single parent I've ever met.
As far as telling fellow posters in an internet forum to "STFU" if they didn't meet certain conditions you've put upon them ... good luck with that!
Attitudes like yours are frightening and dangerous. The bold claim that "this could not possibly happen to me" cloaks a person in a false sense of security.
Accidentally leaving a child in a car happens to good parents. It has nothing to do with parenting skills at all.