I originally thought the statement "I dreaded how he would look" was really incriminating, but I have changed my mind. When one of my kids falls and hits her head/face, I have a few seconds of terror between the fall, and when I am able to look at her face with the hair out of the way. I always imagine a broken tooth or cut to the eye. Something horrific, and it scares the crap out of me.
If I were driving, and just realized I left my kid in the car for 7.5 hours, I would be filled with dread between the time I saw the top of his head, and the time I pulled over and got to my child.
As a parent. I would think you would be in denial and think maybe he could be OK. After all, the child was rear facing, not looking at RH.
And if RH could easily forget CH in the morning, RH could easily think he picked CH up. A different kind of false memory. Why jump to the worst conclusion?