Today I had to leave the house a couple times for about 20 minutes a piece. Figured it was a good chance for some more crate training. After arriving home both times I made sure not to let him out until the whining stopped. Which took a bit.
Watching him was the most pitiful thing. I'll let the photo do the rest of the "talking". The only thing missing from painting the picture of what was happening is the quiet whining every time he took a breath....just like a newborn baby who had cried themselves to sleep.