Blooper

When the Wife first pulls a knife on Carrasco, she is holding it overhand. Next scene, she is now holding it underhand.

When the Wife (Bloom) is fighting Juan (Newman), she falls and hits the camera rig, causing the picture to shake a little.

Before the duel, both Newman and Harvey throw away their gun-belts and the spare ammunition they contained. The duel begins with Newman firing three times at the birds, while Harvey fires four times. Then during the ensuing gunfight, Newman fires four more times while Harvey fires three more times. That amounts to each firing seven times from their Single Action Army Colts, which held six rounds (and as they threw away their spare rounds, neither could reload and neither did not reload). So, each fired one more shot than their pistols were capable of firing.