Character mistake: In the opening credits, the actor Art LaFleur, correctly credited as such in the end credits, appears as "Art Le Fleur" (00:01:00 - 01:15:50)
Revealing mistake: When Jack punches the old lady, he swings way off target, and also 'she' (the stuntwoman, really) turns towards the counter and uses her arms to push herself to the other side. (00:04:45)
Revealing mistake: When he old lady jumps over the counter to attack Jack with a cleaver, she is replaced for the physical struggle by a younger person; you can see her face when the two struggle against the table. (00:04:55)
Continuity mistake: The old lady grabs a knife and throws it at Jack Deth. In the wide angle he lets go of the stove, but in the next shot he's still clinging to it with his left hand. (00:05:05)
Revealing mistake: Jack just killed the first Trancer of the movie; the special effect of the corpse disappearing is not only visually poor to the point of being obviously fake, but it also has a clear mistake in execution; there's a spoon on the kitchen counter that changes position between frames (someone on set was careless and moved it, ruining the composite shot). (00:05:25)
Revealing mistake: Jack just killed the trancer old lady at the diner's. The place was empty and nobody else was supposed to be there, but as he turns away from the charred remains, in the top right corner of the frame you can see someone peek as Tim Thomerson loudly stumbles into the kitchenware on the floor, and then nonchalantly get back to their business. (00:05:40)
Visible crew/equipment: Jack just fished some junk out of the "Lost Angeles" sea. Reflected in the hubcaps, what appears to be (on the empty part of the beach) the camera crew. (00:07:50)
Other mistake: Jack receives a summons from the officers, but he wants to ignore it. He's arguing with his former colleague on the beach. His hair is wet but the suit is dry. (00:08:30)
Other mistake: Jack glances at the front of the baseball card the Consul gives him, and he says "Hap Ashby, 1963 Angels." He has no idea who that guy from 200 years before is, but the card does not say the year, and he's not a psychic. (00:15:55)
Continuity mistake: When Jack receives the baseball card from the Consul, he's holding the other photo from the top, which becomes the bottom in close-up. (00:15:55)
Continuity mistake: Jack (p) reincarnated in his ancestor is talking to the booty call in the Santa suit. He mechanically repeats "Lost souls, yeah..." as he throws the tie over his shirt. He turns around, and in the next shot the tie conveniently adjusted itself going under the collar. (00:18:40)
Continuity mistake: When Leena walks away from Jack (who just 'guessed' her name) saying "Thank God", her hair is a mess under the hat. It's more neat when the camera angle changes. (00:21:50)
Plot hole: The 'medics' carry the body bag that is supposed to have the body of Evil Santa inside, but Whistler vaporized it. Somehow, they fail to notice that the obese man weighs like a feather and the bag is deflated and empty. Moreover, the other Trancers vaporize within seconds from their death, but that one, and only that one, took minutes or even hours to disappear, only with Whistler's direct intervention. (00:25:00)
Continuity mistake: Leena somehow buys Deth's story, and he tells her eventually "So you'll help me." The steering wheel rotates significantly between shots. Same after a brief cut to Whistler when they pull over in front of the "Tropical Tube Tan"; suddenly Deth's left hand on top of the wheel becomes the right hand. (00:26:35 - 00:27:15)
Other mistake: When Jack tries to break free from the tanning booth, ramming his shoulder against the wall causes a severe burn that instantly singes the trenchcoat, but in the rest of the scene he keeps leaning against the same section of the booth without getting grilled. (00:29:45)
Continuity mistake: When the cops catch up with Jack and Leena in the parking lot of the Caheunga Boulevard salon, the first cop says "Freeze." Jack raises his hands, which are in front of Leena. Reverse angle, and he's touching Lena's back. (00:31:20)
Continuity mistake: When Helen Hunt recovers from the "long second" and asks "Why aren't we dead?" her hair changes position on the lapels of the denim jacket between shots. (00:33:35)
Audio problem: At the 'punk' club in Chinatown, the live singer (or yeller) is lip-syncing (and with lots of lips but very little of the synching). (00:38:10)
Audio problem: When Jack hauls Baby McNulty out of the apartment, the young actress (Alyson Croft) 's lines are dubbed over and you can also see she actually bursts out laughing at the turn of the corner. (00:43:00)
Continuity mistake: Jack has just learned about Whistler's evil plan from the TV. He tosses a sleepy Leena her kimono; she is touching her hair with her hand, but in close-up she gets a faceful of silk with no hand. (00:47:35)
