Revealing mistake: When we first see Oliver Reed, we see his shadow first on the wall at a ramp to the pub. As his shadow spreads its legs, we then see him spreading his legs a moment later. Shadow puppetry was used by the director to give the audience the impression that he is ominous and foreboding before we ever see the man himself. (00:54:10)
Revealing mistake: When Buck and the gang ride away from the saloon in Dallas where JC made a few new 'friends', the footage is sped-up for a second just as soon as James Caan jumps on his horse. (00:05:50)
Revealing mistake: When Woody and Sharon are singing their 'Ol Devil Moon' duet, Sharon starts to sit up, but then the shot suddenly changes to them both sitting up, Woody in a fade behind her as she sings.
Revealing mistake: When Philip is in the bathroom at the new house Mike puts toothpaste on his toothbrush and then Philip smiles to reveal missing teeth. Look closely at Philip's teeth and you will see that they are not missing at all - there is black paint on his teeth to make it look like they are missing. (01:14:40)
Revealing mistake: When Matt and Freya are attacking the compound, at one point he goes outside and throws a "hanky panky" grenade at what looks like a garage door. He throws himself over a hedge and a moment later the grenade explodes. When he is getting up, the "ground" is obviously a cushion covered with fake grass.
Revealing mistake: When the historic "Mahna Mahna" sequence in the sauna ends, the girls come out of the building running through falling snow in all their youthful bounciness. The "snow" comes from the left, at a rather extreme angle; if it were real snow there would be an awful icy wind blowing, but the girls' hair is mostly unperturbed, and in the shots that follow there's no snow at all. It's obvious that this snow is just coming from a fan kept off frame. (00:51:15)
Revealing mistake: At the beginning of the opening title sequence if you look behind Silence as he rides through the snow covered forest you can see what looks like a couple of skiers whizz by. (00:05:34)