Continuity mistake: The tiger bites the seat off the suitor's trousers, allowing the viewer to see his polka-heart boxers. When we see the tiger in the courtyard, he has a part of the same boxer shorts in his mouth. So if he bit off the seat of the trousers, shouldn't he have purple cloth in his mouth? (00:11:45)
Continuity mistake: Before the wreath of garlic falls down on Lucy's bedside table, it can be seen hanging on the lamp, but in the previous shot, as well as earlier in the scene, there was no garlic on the lamp. When Lucy grabs the vase from the bedside table a couple of shots later, the garlic that fell down on the table has mysteriously disappeared. (01:09:35)
Revealing mistake: In the chase scene about an hour into the movie, Robert Loggia is shown entering the Liberty Tunnel, driving on a wet road. Note the vaulted round ceiling of the tunnel. Next, we see a series of shots of him in the tunnel, and then a shot of the sun rising over Pittsburgh as he is about to leave the tunnel. Here is the problem - the sunrise shot is taken from the Fort Pitt tunnel on a different day. Note the dry road, the barriers to the driver's left at the tunnel exit and the Fort Pitt bridge straight ahead. There is no place for the driver to make a left turn out of this tunnel. Also note that the POV is from the left lane. All the Liberty Tunnel shots show Loggia in the right lane. The next shot shows Loggia exiting the Liberty Tunnel and making a left turn from the right lane, causing a pile-up. (01:11:10 - 01:12:20)
Continuity mistake: When Robert Redford tips the scrabble letters onto the glass table, he makes "SETE" and "CAST" next to it. To the right of "CAST", under his right hand, are the letters RNY, quite widely spaced. All other letters are tightly gathered above. When the angle changes to under the table, suddenly all the letters are spread fairly evenly around the table. (00:39:15)
Visible crew/equipment: At the surrender of the fort, as the English are marching out, Monroe, says "The fort is yours, Monsieur." Right as he speaks, look between the two horses' heads. In the distant valley you can see what are either two tourist busses or perhaps mobile catering vans. (01:05:40)