Shortly after the opening credits, when Morrow and Depp visit the bar, Curt (Andrew Clay) can be seen next to them at the bar making out with a girl. Later on when they return to the bar, presumably the next evening, Curt is again at the bar with the same girl. When Curt's real girlfriend (the really drunk one) approaches Curt she says its their first night there and he's already flirting with other girls. She must be drunker than she looks since Curt was there with the same girl the night before.
When our heroes first encounter the house detective at the bar, he's in perfect shape. The next day, he suddenly sports a prominent black eye (which will vanish again midway through the film).
The fire extinguisher foam patterns on Reeves' and the Maestro's suits and faces bear no relationship to how much they were sprayed (or even where).
The young woman who is accosted by the house detective that ends up with her bikini top untied is wearing her bikini top in several positions.
The young boy who is using a fishing pole to pull a sunbather's bikini top was inserting the fish hook in the center; when the house detective intervenes, the fish hook was hooked on the side.
In the final scene when Sherly is meditating, she is supposed to be naked ("remove all her artificial layers" to use her words). But when the camera cuts back to her in some shots you can see the back strap of her top.
When the husband is getting a haircut early in the film, you can hear him talking about how is hair is very important, but at the bottom right of the screen, his lips are not moving. There is a change in the audio tone that is subtle, but noticeable as the dialogue was most likely subbed in after filming.