When Briggs selects Rollin for the mission, the dossier photograph is a full-face shot. However, when he tosses Tino's dossier on top of it, it's a shot of Rollin reclining.
When Dan Briggs is seen leaving his car for the briefing, the building in the close-up is completely different from the building in the wide shot
When Briggs is driving to the building labeled "Administration" for the mission recording, the shot shows a 3-story mostly red brick building. The shot changes when he gets out of the car to an off-white color warehouse looking building. The shot then resumes to him walking into the "original" red brick building.
When the briefing tape self-destructs it releases a fairly large amount of smoke in the small testing room Dan Briggs is in. The camera immediately cuts to a shot from outside the room showing Briggs standing up to leave. There is not a trace of the smoke that was released only moments ago.
When Mr. Briggs drives up to the building to get his instructions, the building changes as he exits the car, and then changes again as he walks into the building.
When the IMF team is removing $4,000,000 from the safe, all the bills are $1. Four million one-dollar bills would be much much more bulky.
The IMF use a blowtorch to cut through the metal roof of Wellman's safe. But the flame from a blowtorch would ignite the suitcase containing the money and cause it to burst into flame.
When the explosive charges are being prepared to blow the safe, only one wire is connected to each of them. For an electrical current to flow and ignite the charges, two wires would be needed.
From the top, we can see that there's a difference of a couple inches from concrete to metal. But when they get into the vault, the hole is smoothly cut.
Wellman seems to have known Tino for a long time and to trust him, and Tino is obviously used to catering for organized crime figures. It is never explained why he agrees to work with the IMF.
Before Briggs begins to look at the agent's photos, the reflection of the boom mic can be seen in the glass door when he is walking in living room.