When Han leaves Trish's place and beats up Maurice and his gang, we see Maurice with a cut that is bleeding on the right side of his lip. Later, when Han is persuaded to play football with Mac and the rest, we see Maurice with a scar on the left side of his lip.
In the motorcycle/car chase scene, the right side of the Mercedes (the passenger side where Trish is sitting) crashes into a parked car and the indicator is broken. In the next shot it has repaired itself.
When Mac brings O'Day the newspaper to show him the article of the store bombing, in the over-the-shoulder shot from Mac's POV, we see O'Day flip the paper over to read the bottom half of the story. In the very next shot, an over-the-shoulder POV from O'Day, the paper is in its original position as it was handed to O'Day.
When Trish and Maurice first meet and he begins telling her that she needs to go with him, he stands to the side next to her rather than facing her. When the camera goes for a close up on Trish, it shows him directly facing her, then a moment later it switches back to a wide shot of the both of them and he's facing away from her again.
The film is supposedly set in Oakland, California. There are a number of indications that this isn't Oakland, including the high-rise apartment buildings typical of Vancouver, BC, but the most obvious are scenes in "Oakland's" waterfront that feature spectacular mountains in the near background. Also pointed out are BC Transit buses and Canadian flags.
During the Prison scene, the guards talk in Mandarin, All jails and prisons are operated by the Hong Kong Correctional Services and as such the language spoken is Cantonese not Mandarin as spoken by the guards.
When entering the garage, Han deactivates the car alarm to find the car (light goes on). Immediately after that the main character triggers the alarm again (lights again). In cheap alarms, this might reactivate the alarm, but in other models, this unlocks the passenger door (and a third activation might open the trunk). Since he in fact entered through the passenger door, this is what happened.