Downy is Down But Not Out

Every few months, one of the birds will fly into the glass windows on the porch overlooking the Habitat. The causes vary - panic as a hawk flies through, pursuing another male which is actually a reflection in the glass, being pushed away from the window-mounted feeder by another bird, youthful flight inexperience, and sometimes, I guess, just not paying attention. Most times when they hit, they drop to the ground and immediately fly away.
Yesterday, after the classic clunk at the windows, I looked to the ground below window and found this downy woodpecker. He (it is a male as you can tell by the red spot on the back of the neck) was lying in the ground cover not moving. Resisting the urge to make physical contact to see if he was okay, I grabbed the camera and got these photos.

For two minutes, he laid (pardon the pun) spread eagle (wings out away from this body) (first photo). Then he regained some consciousness and changed his position (second photo). anther two minutes later, he was up on his feet. At this point, he immediately notice me staring down on him and flew away.
I imagine he had quite a headache for awhile. But then again this was a woodpecker known for beating his head against tree trunks.