I caught a 6lb bass last summer in a pond fishing for bluegills. . .with a size 10 hook. The hook never penetrated the fish, it was just wedged in the corner of her mouth. As soon as I lipped her and the line lost tension, it just fell out.
Still, that's one impressive catch with that trailer hook. I'm like you, I can't believe that fish didn't just tear that little bit of skin.