Thank you, Chris Hayes. It now has a name.
This explains better than I could what the Shaggy Defense is. Since I have encountered such things in the classroom before (like this time or this other time), I laughed pretty hard at the explanation.
Today I helped proctor an AP test in the morning (I'll write more about that another day), but in the afternoon I covered a 9th grade English class. 5th period was awful. 6th period was only nominally better.
They had an assignment covering The Good Earth. They decided that they would rather play. Paper airplanes sailed through the room. ("How cliche," I said to them. Then I took the time to explain what cliche meant.) Then they added a paper clip or a pencil to the end of the paper airplane and threw it up so it would stick in the drop ceiling.
I happened to be looking in the right direction when the boy threw the airplane up to the ceiling again. It stuck.
"I didn't do it," he said. "It was him." He indicated the boy on his left.
"I saw you do it," I said.
"But it wasn't me," he repeated.
"Are you really using the Shaggy Defense on me?" I asked.
I have no idea if he knew what I meant, but I don't care. He admitted it! And the conversation was over.
Oooh, Shaggy Defense. I'm going to use that one again.