Other mistake: While inspecting the gems from the robbery, Stephen Baldwin is looking through the wrong end of the jewellers magnifying glass.
Continuity mistake: Near the end, when Agent Kujan realizes who Soze is, he drops his coffee cup and it breaks in slo-mo. If you look closely, you can see that the bottom of the cup does not have the red writing on it. (I will not give away what the red writing is, as it may be a spoiler).
dbfilmsContinuity mistake: In the scene where Dean Keaton is outside the police station talking to Edie Finneran, the cigarette that he's smoking is in his mouth, then the shot changes and it's magically sprung from his mouth into his hand. (00:25:15)
alargemangoContinuity mistake: When the suspects are in the garage after Saul, Saul drops a gun and Keaton kicks it over to McManus. However in the next shot McManus picks up a different type of gun.
Continuity mistake: When we first see the Hungarian guy lying in the hospital he is burned over most of his face, however his eyebrow is still there. In a later scene, his eyebrow is gone but his eyelashes are still there.
Continuity mistake: When McManus and Keaton are clearing out the boat, the time of day outside (as shown by the daylight) changes from shot to shot. It should be dark during the entire scene.
Revealing mistake: In the flashback, when the boy has his throat slit, there's no blood or wound.
MikeHOther mistake: The burned guy who's supposed to be Hungarian keeps making bad language mistakes, although his pronunciation is great.
Answer: Keaton doesn't believe in Keyser Soze, and is so convinced that Kobayashi is the one pulling the strings and manipulating them. They figure that if they take HIM out, they are home free.