Carrie has white underwear on at the beginning when arguing with her husband, until caught by the baddie who strips her, with what appears to be intent to rape, revealing dark underwear.
When Gordon searches for Carrie towards the end of the film his pants are inexplicably torn in the crotch area for many shots, then his jeans revert back to normal and intact later on.
When Carrie smashes through a window after escaping the rooftop, her trajectory doesn't match the way she lands in the room between shots.
At the beginning of the movie Carrie is shown flying the helicopter with close-upshots of her long red nails. All shots after and throughout the movie she is shown to have red nails of natural size.
When Jimmy gets killed by the rocket launcher his body is partially outside the car, but later the door is completely closed and he's said to be inside while it burns.
An ordinary helicopter charter pilot wouldn't be wearing a G-suit or any part of one.
Throughout the shootouts, the number of shots are more than the weapons can perform without reloading.
When a hostage is shot, the "blood" that spurts out of the wound is clear, rather than red; evidently the blood pack that was used was accidentally prepared without coloring.
Throughout the movie we are shown the 26th floor as the highest point of the building, but ads, descriptions and talk throughout the movie state 86 floors.
When the villain is shot out the window and lands on the car, his descent shows a consistent head first fall while impact is more on the back.
No matter where the Heliscort helicopter lands in Los Angeles, it is always the same rooftop. Noticable patches of paint are missing on the building in the foreground in each landing sequence.
It's obvious the police helicopter and the charter helicopter are the same ship. The paint schemes and even the ID ("N") numbers match.
When Hakim meets Wink for the first time in the helicopter, he quotes from Shakespeare, "for when a world of men could not prevail with all their oratory, Yet hath a woman's kindness over-ruled." Wink identifies the source of the quote as Henry IV, which Hakim confirms, but the quote is actually from Henry VI.