when I mentioned locked in a shed or car, I was thinking heatstroke(hyperthermia)
My grandun, about the same age, can easily get in a car, but often finds it difficult to get out, depending on which car & handle. So, hmm.
Quite a few aren't thinking an accident, at another home, that was then staged , etc
BUT what IF something did happen elsewhere, and the person(s) panicked because they are involved in some type of illegal activity themselves or involving the home...and to even call 911 for an emergency would bring about charges/arrest if that activity were discovered.
Back in the day, I associated with ah, some rough folks, who I daresay would have done just that, anything to divert from themselves, to avoid LE around them or in their home. 'Nice, friendly' folks, but callous and cruel, and very CYA