Not My Fault

A husband comes home to find his car wrecked, the result of it driving straight into the neighbor's tree. Panicked, he runs to the scene of the accident, and is relieved to find his wife okay, and apologizing profusely to the next door neighbor.
"I just can't understand what happened!" he hears his wife explain.
"How did this happen, honey?" asks the husband.
"Oh, Roger!" the wife cries, hugging her husband. "It was awful! I'm so upset! This accident isn't my fault!"
"And why do you say that, Mrs. Smith?" asks the irate neighbor.
"Because just before I hit your tree, I honked the horn!"