Minor Plot hole: John Anderton enters the PreCrime building by using his old eyes on the scanners in order to download his potential minority report from the female precog. However, it is surprising to see that his eyes still have security clearance in a building where all the personnel is desperately trying to put in jail.
Major Plot hole: John Anderton, unlike all the other PreCrime accused criminals, knows the exact time and city of where he is supposed to commit murder. He could simply have left the city and waited a day for the murder to not happen and go back in Washington to expose the flawed system. This was the most efficient way to prove his innocence...and yet he put all the effort into finding the place and man he was supposed to kill.
Major Plot hole: Lamar Burguess, the creator of PreCrime, creates a plan to murder someone and get away with it by hiring a psycho to kill a woman and then, after his inevitable arrest by PreCrime officers, do the murder himself in the same clothes and manner he instructed the killer to do. Although it is true that the precogs' vision would be the same.....the murderer wood ball would show a different name: Lamar Burguess.
Major Plot hole: Precogs don't predict the future. If they did, they would show people almost getting killed and being stopped by PreCrime forces. They thus predict a future that is very similar to reality, but not reality.
Plot contrivance: Cars that are freshly constructed out of factories are full on gas and ready to go!
Plot contrivance: In this movie, people who fail to kill their victim but were going to are accused of murder......instead of attempted murder.
Plot contrivance: It took 6 years for the U.S department of Justice before investigating the PreCrime system in Washington to see if there were any flaws or problems. Like the drug fueled and objectified teenagers used as precog machines.