When Wade punches Benny in the nose, Wade's fist stops quite a few inches from Benny's face, obviously not touching him.
Although the movie is supposed to take place in New Jersey, the tail number on the helicopter begins with the letters YR which indicate it is registered in Romania, where the movie was filmed.
When Francine is playing the piano after dinner, her hands on the keyboard do not begin to match the music that is being played.