When the professor dumps his food in the wormhole and it falls on his head, he sticks his left arm in the wormhole to clean himself up. However, it is his right hand, not his left, that cleans up the mess.
After Bender and the two bums land on the planet, the camera makes a pan from the left to the right (back to them) and shows a red robot walking toward them. The camera stops on Bender and he talks long enough for the robot to pass by, but the robot never does.