When Paul is putting shaving cream on with the brush, he lathers it on relatively thick in the frontal shot, but then when the scene cuts to the side shot as he begins to shave, the cream is on in a thin, uniform layer.
After he uses the butter, Paul rests alone on the floor on his left side. Next shot he appears on his back.
When Jeanne disappears during her bridal gown fitting, Tom goes running down the street to find her in the pouring rain. As he gets about fifty feet from the camera, he sudden runs into a section of the street that is dry, and there is no rain coming down. Apparently, he ran past the maximum range of the rain-making equipment being used for the shot.
When Paul monologues with his dead wife lying in bed, Veronica Lazar's chest can be seen moving up and down at a breathing rate.
When Paul monologues with the Rosa, as he leans on her to say "Rosa, I'm sorry.", she blinks.
When Paul and Jeanne are at the sinks together, she says, "I prefer to be a whore." Her lips do not move during that line.
During the Tango contest scene, Paul's clapping doesn't match the soundtrack.
As the camera pulls away from the balcony at the end, a crew member and a lighting array can be seen reflected in the glass panel of the right balcony door.
The bottle of "bourbon" is actually Jack Daniel's Tennessee Whiskey. (This is a common error, even in the U.S.) This whiskey has all the properties of a bourbon, but as it is filtered through charcoal before being barreled, it is a Tennessee Whiskey, not a bourbon.
Paul does not know how to sharpen correctly a barber's razor on a leather strop. He turns over the razor for every stroke on its edge instead of its back, so blunting the edge with every stroke instead of sharpening it.