(at around 1h 8 mins) We're in Vroman's bar, an up-tempo group bringing it on. We can hear a piano (conventional, vs. a keyboard) player going at it, but when we get a shot from behind the piano player, he's moving his body up and down as if he's "into it" and playing, but in looking at his hands, he's barely flinching, and he's certainly not playing it.
During the "class isn't something you buy" scene when Jack & Reggie are following Luther, Jack says to Reggie class isn't something you buy and then says "...look at you, you've got a 500 dollar suit on and your still a lowlife." But earlier in the film when Reggie is first released and is wearing the suit he tells Jack that it was a $900.00 suit which Jack should have known later in the film.
Thirty minutes in, Jack and Reggie are driving to get Luther. Luther is visible a few car lengths ahead of them, driving Reggie's car. The car wasn't even picked up from storage until much later in the movie. It's the same scene used when they're tailing Luther about an hour into the film.
Reggie is handcuffed when Jack throws him into his car after getting him out of prison. In the next shot, Reggie's left arm is stretched out along the back of the seat and his right arm is hanging out the window. In the following shot, he is handcuffed again.
When Reggie takes the knife from the redneck, he closes it and places it on the bar with his right hand before breaking the glasses and being told where Billy Bear's girlfriend lives. When he turns around and talks to the people in the club, the knife is clearly still on the bar. He then walks out to the street where he takes it from his back left pocket and gives it to Cates.
During the alley fight between Reggie and Jack, Jack swings at Reggie several times, but misses and stumbles amidst the trash cans and garbage up against the brick wall of the building. Jack then takes another swing at Reggie with his left hand. However, one frame later, Reggie is shown being hit by Jack's right fist.
While looking for Luther, Jack and Reggie visit an apartment in The Mission and learn they should look for their quarry "just around the corner in Chinatown." In reality the Mission is 3 miles from Chinatown.
There is most likely no way a battery would stay good for three years only being charged once per month. Once a battery goes through 7 cycles of running all the way down it is shot. About the only way a battery would stay good this long is if it were a modern day battery on a trickle (constant) charger. Very doubtful the car would have started after 3 years without a full charge anyway.
The goof items below may give away important plot points.
During Lt. Hayden's rant, he says that he has "five deaths related to Ganz." At this point in the film, Ganz and Billy have killed at least seven people - the two guards on the road gang, Henry Wong, Detectives Algren and Vanzant, the cop in the MUNI station, and Luther.
Throughout the whole movie, Ganz is holding Luther's girlfriend Rosie hostage. She is even with Ganz on the bus when Luther comes on board to give Ganz the money. However, after Ganz shoots Luther and the bus chase begins, she is no longer seen. Not even in the interior shots of the bus as Ganz is shooting at Jack and Reggie. Later on Keyhoe tells Jack that the bus was abandoned in Chinatown but does not mention Rosie. From the point that Luther is shot until the end, there is no indication of whether or not Ganz killed Rosie or let her go.