The most notorious example i can think of is him thinking he yelled Carrie on Star Wars.
Star Wars: A New Hope: The “Carrie!” Blooper
https://www.youtube.com/watch?v=z3NZ2zNLIbA
I guess it could just be a “yay” or something like that, but it really does sound a lot like “Carrie” to me. And as far as slip-ups go it makes a lot of sense.