Thunder "attacked" me too and bit my in my temple when I was younger.

But its because I startled him, he wasnt punished or anything. As soon as he herd me cry he came over and was licking me. Hes never done it again and he is the sweetest dog.

Dogs dont remember things liek that especially later in the day. So locking him in the garage did not but be cruel on your part. Also he wouldnt just attack while you all are sleeping so it was pointless..

I think it would be stupid to have your dog put down for that, its not like hes constantly attacking or anything.