Was it a Head Shot, Heart/Lung Shot or Both?

My neighbor noticed that chipmunks had burrowed beneath the below pictured retaining wall and gave me a call. I setup 12 yards away and at 6pm the chipmunk emerged from a hole in the lawn and ran along the bottom of the wall, I took aim and squeezed the trigger, there was no convulsing; he simply dropped on the spot. I figure that it started as a head shot and finished as a heart/lung shot. Again, I was shooting at a downward angle and as usual the pellet achieved 100% penetration. It entered behind the eye on the left side and exited through the shoulder on the right side. Thanks to the wall I was able to retrieve the pellet. You can see the rifling on both the head and the skirt. I don’t know if the skirt deformation was caused by the chipmunk or the wall. (12yds, 827fps, 19ft/lbs. at target) 

1528400581_21128579935b198ac5930d54.62508853_Retaining Wall.JPG
1528400599_17945906035b198ad70c6705.34397238_Chipmunk Entry 12yds 6-6.JPG
1528400610_12754020995b198ae227e5c6.53537920_Chipmunk Exit 12yds 6-6.JPG
1528400623_19140759565b198aef26d980.54679564_Pellet 1.JPG
1528400632_16056797825b198af8dc84c4.38708044_Pellet 2.JPG