I think I finally figured it out. It was kind of bothering me what this wasn't a quick kill shot and was really interested to see the pellet POI and path.
If you look at the last pic that I took before my wife prevented me from taking more (including the other side of his head), I think it gives me the clues I was looking for. I took this close-up pic because his lower jaw and mouth on the right side looked strange to me when I flipped him to both sides to examine it, and remember it was pitch black out last night and was using a very small MagLite flashlight (my big MagLite has disappeared!).
Today I zoomed in and enlarged the pic and I believe I can see the exit wound the Crow Magnum made. It seems to have exited through the part where the upper and lower jaws meet and it makes perfect sense now. The POI seemed have been right below the left ear from what I saw last night, and because I was up on a 2nd floor window aiming down at him, the pellet traveled downwards and exited out near the back of the mouth. You can see the exit hole right behind the upper teeth that are sticking out. His mouth was actually closed shut on the other side and looked much better.. The g-hog was slightly at an angle facing away from me just a little when I took the shot, so the trajectory of the pellet through his head makes sense that it exited slightly forward from where the POI was on the other side. I was almost certain that the heavy CM traveling at 745-750fps out of the muzzle, should have been able to penetrate completely at such close range of 23-24yds. The pellet probably just slightly missed the brain, not fatal at first, but caused enough trauma in the head area and internal bleeding as is evident from the blood at the nose, etc. that eventually after a min. or so took its course. It had rained here a few days ago so I assumed that had washed away most of the blood which made it harder to solve the mystery of the pellet impact..
So what do you guys think of my forensic evaluation?