The fact that the parents looked up online how long it takes for a child to die proves that it was no accident. They are very sick people and should be punished and be forced to die the same way. It is no accident if you just recently looked up information on the effects. If he was just looking for information it would have made him even more careful not to do it.
Being a mother myself, I could never understand forgetting that my child is in the car. Even if I'm emotionally distraught, I have never forgotten my child. With all the evidence that has come to light, there is too much that points to premeditation. I believe this is another case of a parent trying to make it look like an accident so they could get away with outright murder.
No, the toddler's death in a car was not an accident, because the man knew what he wanted to do. The man googled the subject shortly before the toddler died, because he had the whole thing planned. The man was also cheating on his wife, and obviously just did not want the responsibilities of a young child.
I cannot see what would make any father or mother feel the need to research how long it takes a child to die in a hot car. I am very overly cautious and protective of my children, however that is something I cannot see any parent researching for any reason other than to use the information that may be found in a negative way.