In sports, saying a team "laid an egg" is a popular expression, used when a favored squad comes out and doesn't play up to its potential. Usually, "laying an egg" means the team loses the game.
Michigan hasn't really come out flat this season under Jim Harbaugh. At 8-2, it lost its opener at Utah and in the final seconds against Michigan State. In eight victories, the Wolverines have pretty much played as they are supposed to.
So perhaps that's why Harbaugh had this funny response today when asked why his team hasn't "laid an egg" following a road win at Penn State.
Harbaugh is never boring. He's...unique. But not boring.