When the delivery boy drops off a bag of groceries for Ray Quick, he opens the door, which is at the corner of the building, and picks up the bag. When he goes back inside and closes the door, there is a wall and window next to the door, not the building corner.
When the door is unlocked and opened into Ray Quick's hotel room, the room number changes from the left unopened door to the right opened door, the room number font type changes and a peep hole appears in the center of the door.
When Ray and May are escaping his compound in the escape tunnel, it shows part of the concrete ceiling give way and collapse on the tunnel floor. The next time we see them, moments later, the escape tunnel is clear of all debris.
When Ned sarcastically demonstrates his expertise in the police station, he starts the bomb timer at 20 seconds and mouths off for at least 10 seconds. But when the timer is shown again it is ticking down from 13 to 12.
In the 1984 prologue, Ray and Ned are on a CIA mission in Colombia and are wearing military fatigues. As noted in the Tom Clancy novel Clear and Present Danger, which was set in Colombia during the 1980s, fatigues are not commonly worn by legitimate military personnel in Colombia and would not be used by covert operatives there. The proper "blending in" outfit in this situation would be some kind of khaki gear.
The first time Ray calls May, he looks at her message on his computer with her phone number. The number he dials is not the same one that is on his computer screen. He also doesn't put any money into the payphone.
When Ray calls Ned at the police station, he times the call so that he wouldn't be 'traced' and clears it after precisely 58 seconds. The call would have been via digital exchange and the number would have been displayed instantly as it is a feature provided for billing purposes. Previous electro mechanical (strowger) exchanges required time for the call to be manually traced through selector banks and distribution frames, often through several different buildings miles apart and always referring to wiring records. The time taken varied enormously and depended upon the skill and knowledge of the engineers. Strowger exchanges are now obsolete and would have been highly unlikely to be operating in the area of Florida where the movie is set. Hollywood even today has not moved on from this antiquated and outdated plot device.
When Ned's team first walks into the hotel room, the standard Ma Bell message "Your call cannot be completed as dialed. Please check the number..." can be heard from the off-hook phone. A few seconds later, it changes to the more logical "If you'd like to make a call, please hang up and...." In either case, however, the Ma Bell messages would not be heard through a phone connected to a hotel switchboard.
When Ray and May are at the Hotel getting ready to make love she tosses her purse on the bed and it can be clearly seen, but a few seconds later while they are undressing each other the purse has vanished.
The scene in which Ray sets a trap in his high rise balcony hotel room overlooking the water was spectacular, but from a construction or physics perspective it was preposterous. No amount of explosives placed on the surface of the floor, walls and ceiling could have caused the balcony to break off cleanly as depicted. Ray would have had to have hired crews to use heavy equipment to drill into the concrete and then place explosives inside the concrete. Obviously the hotel would not have cooperated with Ray's remodeling.
After confronting Stallone at the restaurant with a gold colored knife, Thomas (Eric Roberts) gets in the car on the left side of Sharon Stone. When the car pulls in to her place he is on the right side of her.