Visible crew/equipment: At the L.A. Convention Center, just before Castor Troy (as Sean Archer) disarms the bomb, there are a few shots of all the extras evacuating the area. In the interior shot, that looks out through the glass doors onto the street, the tracking crane arm with a seated camera operator and camera on its platform is visible as it shoots an exterior crane shot of all the extras, which was seen among the previous shots.
Continuity mistake: As the FBI and Richard Gere rush to the hospital to save the First Lady they are flying in a helicopter. You see a shot of the helicopter flying over buildings then it cuts to dialogue inside then back to the landscape shot. However in the first shot the helicopter carries the number "28" on the side. When it cuts back after the dialogue it has "29" on the side of it. (01:36:35 - 01:40:00)
Continuity mistake: When Alex's Dad arrives home at the end of the film, he hands Alex a remote control car box. Between a wideshot and closeup the box turns around 180° in his Dad's hands. (01:32:10)
Revealing mistake: During the honeymoon sequence at the end of the film, if you look at the right top of the flowers in the vase during the "flowers covering nipples" bit, you can see a bit of red duct tape covering Liz Hurley's nipple from behind the flowers. (01:22:20)
Continuity mistake: When Diamond Dog puts the hat on in the plane after it's hijacked, he puts it on backwards.A second later, it's on straight without him turning it around. (00:43:55)
Revealing mistake: The stunt double's hairline is quite different than the actor's, when Bud White holds him over the balcony. (01:53:40)
Continuity mistake: When Robin steps foot into Poison Ivy's lair she is laid out on her flower bed. If you look at the sleeves of her costume, the ends of the sleeves are fringed in a simple leaf like design. Robin spurns Poison Ivy's affections, and an enfuriated Ivy pushes him into the lily pad pool. She is then confronted by Batman, and a soon to arrive Batgirl. Now - look at the huge, obvious, black rubber "thorn" bracelets that suddenly appear on each of her wrists. (01:37:25)
Continuity mistake: When Celine is tied up playing blackjack, the position of the rope holding her varies. We see for example that the number of times the rope crosses her chest goes from three to four and back again.
Continuity mistake: Talking with the feds about the case, Cross says "This guy's a collector." Kyle Craig in the background goes from holding a pad to a folder, and then closes it multiple times when it was closed to begin with. (00:24:00)
Continuity mistake: When Bill Murray is talking to the dead guy in the chair, the dead guy's eyes are open. But from a side shot, they are closed. (00:33:00)
Continuity mistake: In the sequence with Terence Hill and Marvin Hagler giving chase to the bad guys, when the baddies break the guard-rail and supposedly drop one level, the lights of the chasing car are still fully visible through the back window before the good guys take the same dive from the highway ramp.