Corrected entry: Vincent cuts the power to the building, thus alerting Jada Pinkett Smith. He did not know she was being warned on the phone and lost all his element of surprise. He could have just sneaked up on her without having to kill the electricity.
Corrected entry: When Max is tied to the steering wheel, he starts hitting the horn with his head and yelling out the window. When you see the cab from behind, the flashers are on. With his hands tied the way they were, there was no way he could've turned the flashers on.
Correction: There's a chance Max turned the flashers on since he made a stop and was waiting in an alley. They may have already been on just before Max was tied up.
Plot hole: Near the end Max calls Annie, using the number on the card she gave him, to warning her about Vincent's arrival. But why is there on the card the number of the law library on the 16th floor and not Annie's office number or her cell phone number?
Suggested correction: The number on her business card is her office line. A lot of office phones are set up so they ring in multiple places throughout the office. A light will blink on the phone letting you know which line is ringing. The line is connected to her office phone, which we see Vincent looking at in her office when she was on the phone with Max, which then gives away her location. This is a very popular way of having phones set up in offices, as it eases communication between co-workers. If one of her co-workers wants to talk to her while she's in the library, they can simply dial her line instead of going up two floors. Furthermore, it is also possible that her cell phone number could be on the card. But Max tried the office number first. He would likely have tried the cell number next, had she not answered.
Stupidity: When Max is in the federal building and shoots Vincent, he and Annie get into the elevator and go to the first floor. Knowing that Vincent would take the stairs down to the first floor, why didn't Max and Annie stop on the 12th floor, or any floor, get out, and call the police from there. It would have taken Vincent quite a while to figure out what floor they were on, and they could've kept moving from floor to floor and Vincent would've never found them.
Suggested correction: Considering they had a head start to the elevator, I would have done the exact same thing instead of risk staying in the building with an experienced hitman. Going floor-to-floor as you suggest while being hunted by a killer is a bad idea. Let's not forget Vincent also killed the phone lines. Maybe only the phone lines to her office? Who knows. But would you want to get out on the 8th floor to see if the phone will work on that floor, and then wait for the police? Plus in situations like these, you're not thinking like that. Your instinct is telling you to GET OUT. Getting outside in public is a much better idea than playing cat-and-mouse with Vincent in the building.
Trivia: The film was almost entirely shot in high definition. Director Michael Mann states he did this to capture the night scenes more vividly.
Suggested correction: The number of movies shot in less-than-HD could be counted on one hand.
I believe it refers to the fact that Collateral is considered to be the first major movie to use a digital camera, not the traditional film support.
Corrected entry: When the train leaves, you can see Tom in the window in the front of the second car. Before that they had a huge shoot out, yet the engineer one car forward is unable to hear the shoot out and completes his stops with 30 bullets and a dead guy, not to mention the passengers who didn't seem to care.
Correction: In actuality the gun fight is only about 4-5 shots each person. In the film it is very quick and then its over. Being in a closed booth the sound would have been reduced significantly. The engineer could have assumed (with not seeing the incident as well) it was just a ruckus or something on the tracks as it was so quick. There are a number of loud noises being on a train so might have just assumed it was a loud noise. With regards to the passengers that we see, Tom and Jamie pass the only remaining passengers before the stop where Tom holds his gun out the door to stop Jamie Foxx. In that stop the passengers behind would have likely exited the other cars to avoid any trouble as they had seen the guns being carried.
Corrected entry: In the final scenes as Annie and Max disembark the train, the marquee reads "Today is Sunday, June 25, 2004." June 25, 2004 was a Friday.
Correction: The sign says "Jan 25", meaning January. January 25, 2004 was a Sunday.
Corrected entry: When Max and Vincent are at the hospital and have entered the elevator, Vincent is holding the briefcase in his left hand, but the hand/fingers that press the button on the elevator is the left hand/fingers not the right, then the camera cuts to a wider shot and Vincent is lowering his right hand from the button even though he pressed the buttons with his left (the hand holding the briefcase). (Slow motion necessary.) (00:46:40)
Stupidity: Vincent's choice to cut the power to the building that Annie is in does nothing but waste enough time for Max to save Annie. It would have been easier just to go up to kill her and he probably would have gotten away from the police if he did so.
Suggested correction: It also slows Annie and Max down by forcing them to walk in the dark, and also, at this point, Vincent is really torn up from the crash, and the mere sight of him is going to make Annie very suspicious or even afraid, unless the power out (which for all she knows is just from the building) gives him a plausible reason for being so mauled.
Revealing mistake: In the train scene if you look closely at Vincent's ear as he steps off the train ready to shoot Max and Annie, it looks like he has an earpiece or some kind of small blood pack in his ear. (01:44:05)
Suggested correction: He could, in fact have an earpiece/hearing aid in place, and what with the wild night he's been having, the accident and all, a blood pack is not out of place either.
It's visible that just a little amount of blood dried up in the ear. Not any earpiece or blood pack.
Correction: So what? Then that was a questionable choice made by Vincent, not an error in the movie.