Unusual Bird: Red-winged Blackbird with Deformed Bill

I saw a small group of Red-Winged Blackbirds in my backyard during a feeder watch session on Dec. 17, 2016. This bird stood out because of the shape of his bill. Although the lighting was terrible, I caught a few photos of it. When he opened his mouth while scratching, the difference in the top and bottom bill is very evident. The flock ate at the feeder for a few minutes and then flew away. Although this bird flew toward the feeder with the others, I was not able to see him again. I wish I could have seen how he eats.