Revealing mistake: In the big speedboat scene near the end, when Cage is hanging off the side of the boat the stunt double is obvious in wide shots, where the entire boat is visible from above. He has big long sideburns, which are in stark contrast to Cage's short hair, visible in closer shots. At various other points in the movie, stunt doubles appear of much different physical builds than the two actors, with markedly different hair colours, and I seem to recall that at least one of them had facial hair.
Revealing mistake: At the boat scene when Archer is holding on to the red boat and is skiing on the side, you can clearly see the waterproof boots he is wearing.
Revealing mistake: When Loomis comes upon Castor grieving over Pollux's body and says "Sir, why are you so upset? Its just Pollux Troy", you can see discoloration of a lump on his forehead which is makeup covering the blood pack where Castor will shoot him.
Revealing mistake: In the speedboat crash where the film is slowed down, there is a medium shot of Troy and Archer flying through the air. It is very obvious that neither are the true actors.
Revealing mistake: In the scene when Castor Troy kills Agent Winters the sky is blue. There is only one cloud just above the fuselage. This cloud doesn't move, at least not that fast as it should as the jet is near take-off speed. The aircraft stands still when the actress falls out of the jet. In the ensuing shot, when the dummy falls out, the sky is overcast and the aircraft moving again.
Revealing mistake: When Castor is pushed into the blowing heat from the plane engine by Sean and is thrown back, the man that lands against the grill is so obviously the stunt double; he has a different hair cut than Castor and really doesn't look anything like him.
Revealing mistake: At Erehwon, Sean (as Castor Troy) is given steel magnetic boots to wear, for the prison's important security feature. There is a close-up of these heavy duty boots during his 'exercise'. Then, when he is taken to the clinic there is another close-up, and there are a number of changes to the boots style. More importantly, one of the side "bolts" has fallen off, revealing that it was merely glued on the prop boots.
Revealing mistake: Just as the red speedboat heads toward shore, before it crashes, the white and red truck cranes are on the dock and the white crane arm is angled backwards over the dock. In the shot facing the speedboat, as it explodes, that crane arm is now angled the opposite way, over the water, since it was used in the stunt.
Revealing mistake: In the hall of mirrors Travolta runs behind the mirrors in order to get the drop on Cage. Cage starts shooting, but when he stops and lowers his arm the muzzle flash (and possibly the gunfire as well) from his gun continues as if he's still firing.
Revealing mistake: When Cage is shooting Travolta with the Uzi type weapon in the room with mirrors, the gun has no muzzle flash in several shots.
Chosen answer: It's obvious that enough time hasn't passed for a trial of such magnitude to take place, meaning that the brothers have been remanded in custody to await trial. They should have been arraigned but we don't see that onscreen.