Revealing mistake: When Sonny is punching Carlo under the spraying fire hydrant, he misses an audible punch by at least six inches. (01:43:30)
Revealing mistake: When Moe Greene is shot through his right eye, the eyeglass is cracked, but has no hole where the bullet penetrated the glass. (02:33:50)
Revealing mistake: When Michael is riding in the car with Sollozzo before the assassination, notice the headlights in the rear window during the close-up. You can notice that many of them move directly on top and underneath each other, impossible for real car's headlights to do such a thing. (01:21:25)
Revealing mistake: When Michael calls Sonny, after he finds out that his father has been shot, the phone booth he calls from has a broken dial - you can see that the dial is off center and would not work in that condition. (00:45:00)
Revealing mistake: In the kitchen scene where Sonny is talking on the phone one can see that the lower portion of the telephone handset has no internal parts. (00:48:50)
Revealing mistake: When the hooker is lying dead and the senator is sitting on the bed, the sheet moves as she is taking a breath.