The 5 year old may have thought he Dad was sleeping. If this man died so quickly, his heart or general condition may have slowly been running down, meaning the boy was used to seeing his Dad sleeping or resting much of the time. Not everyone teaches their toddler how to use the phone that early, or perhaps the phone was not within reach.
I can’t imagine how I would have reacted at that age, but lucky for the baby, he did finally let someone know who then chose to ‘get involved’. That’s another thing. Some folks these days drill it into their kids heads Not to Talk To Strangers, EVER!
A few years ago I read about a Boy Scout who was swept downstream after falling out of a raft. He was wearing a PFD and made his way to shore to be found a couple days later. Where he was found had been searched. He said a guy came by on a horse shouting his name but since he was a stranger, the boy hid.
I teach my trail life kids that if they are lost and someone comes by shouting their name. It’s ok.
As soon as our kids were old enough to recognize 911 on the phone, age 3, I called the sheriff’s office and the deputy let them practice calling.