The blood comes off Sebastian impossibly quickly; he has no time to take a shower, and blood is somewhat sticky (though not as sticky as fake blood).
The blue spray on Sebastian's arm when the scientists tried bring him back to visibility disappears when he turns back to being invisible.
Before Linda uses the flamethrower, the elevator doors were almost fully shut. The next shot where she uses it, the doors were wide open, beginning to close.
At the end, Sebastian pulls Linda through a water puddle. Her shirt becomes dark because of the water absorbed. The next shot, it's light again.
When the mask is made and Linda cuts out the holes for the eyes, they are rigid and angular. In later scenes they are perfectly smooth ovals.
When the latex mask is being poured over Caine's face, it's smooth on top as if he were bald, instead of getting caught up in his hair.
An injection into a vein will first reach the heart, then the lungs, after that return to the heart and finally distribute through the body. The sequence shown with the Gorilla and Cain returning from invisibility was anatomically incorrect.
The latex mask has no nasal or ear holes cut out - yet Caine can hear and breath without any problem.
Due to braking mechanisms and the fact that the elevator floor was at the same level as the lab floor, the fire would not have pushed the elevator upward. Instead it would have come up through the access panel that they opened, and possibly blown the top of the elevator off.
The gorilla is referred to as "she" yet when "she" becomes visible, it has a silver back. Silverbacks are the dominant male of a gorilla group.
Since the viewing goggles used infrared radiation for seeing invisible objects, they could not see through a metal locker. However, the woman in the locker was leaning against, and hence warming, the door, and its her warmth that was shown.
While a defibrillator is of no use if a patient has truly flatlined, a patient in a "fine v-fib" rhythm can appear to have flatlined but still be revived with the paddles. Therefore, when in doubt, the Advanced Cardiac Life Support guidelines call for administering the shock, though it's not the treatment of choice.
When the team tries to make Caine invisible, he tears off all the sensors and wires from his chest. Yet the surrounding machines continue to display his heart rate and blood pressure.
When Sebastian is injecting himself with the serum, air bubbles are clearly visible in various shots. Anyone who knows how to administer an injection would try to get as much air as possible out of the liquid before injecting it.
When Matthew Kensington does CPR on Sebastian Caine, he is pumping his stomach not is chest. His hands are in the wrong position.
Sebastian Caine's mask has no nose holes, which would make breathing hard for him.
At the beginning he says they are to be there early and several people say it is around 8:00 AM. When he is driving to the lab the shadows clearly show that it is around mid-day.
When Sebastian is working on the molecular configuration in his apartment at the beginning, you can hear the TV on in the background. Later, when he has his eureka moment, you can see snow on the TV, implying that he works so late that the network signed off. Most if not all TV stations/networks in the US are on 24/7/365 in the 2000s when this movie takes place.
Steadicam operator reflected in window when invisible Sebastian enters the observation room to touch Sarah.
When Sebastian is stalking his neighbor, there is a brief moment where you can see the reflection of camera crew in the window looking into Sebastian's apartment.
Numerous problems inherent to the "invisible man" premise are completely ignored. Some examples: Since light passes through the retina Sebastian would be blind. The soles of his feet would be visible from the dirt picked up by walking barefoot. The food he eats becomes immediately invisible.
Caines colleagues find out about his rigging the thermal camera; they take out the altered circuit board. Caine later on looks at himself in the now restored camera, yet nobody confronts Caine about his manipulation, neither does he bring up the topic, even if that he now knows that they are on to him and they know that he knows.
When Caine injects himself with the fluid to make him invisible, you see bubbles going through the tube into his arm. These bubbles, once in his veins, would cause severe pain (though are probably not enough to kill him). Hence doctors in real life flick the bubbles to the top of syringe and squirt them out. At the least, a medical professional injecting air would be highly unprofessional.
When the other scientists do CPR on Caine, they are not in a position to do effective compressions. However, *real* CPR breaks ribs, so this "acting" facsimile ought really to be allowed.
After Sebastian has become invisible, the 3 main characters are walking him to the observation room where he sits down on the bed. After Linda says the line "about time the shoe's on the other foot", she nudges him down onto the bed, turns and briefly looks directly into the camera, then obviously realizing her mistake, quickly looks away.