The sweat spot on Audrey's back changes when Joe talks about fidelity and Paul plays the piano.
Close-up of "Young Joe" with hazel eyes is shortly followed by a close-up of adult Joe with blue eyes.
Toward the end of the table read of the script, while all voices are silenced and only the sounds Joe is making are heard, Paul gives Joe a victory sign by shaking his two hands together. Moments later, Joe's watch shows that it's 3:05pm. When the reading is over, the producer says, "Take an hour and a half for lunch. Back at 3:00."
When Joe is being restrained in the hospital bed, they did not use a slip knot on the wrist restraint.
In a closeup of the back of Joe's head during Bye, Bye Love number, a large strip of Scotch tape is inexplicably running across back of his head.