Wow I had no idea they were like that. We have them around too, thankfully only my game camera has picked up a screech owl and it was at night after everyone was locked up.
Hard to beleive a great horned owl could do what you described maybe a raccoon they can open just about anything that is why we have to make sure what kind of locks and bolts we use to keep out birds safe in their houses. i am not disputing what you aresaying just having a hard time thinking of...