I guess I was wrong about the flying squirrel being disturbed by the boreal owl we had last week. The squirrel has been visiting our feeders regularly since, and we've even seen a pair of them on occasion. His eyes are actually black, but they're so large that when the flash hits them, they turn completely red. The photo has been edited so they're white instead.
My wife took the photo. You can see some more of her pictures at her Flickr page.