Visible crew/equipment: When Luc shows El Niño his "666" marks and Niño says: "Well, all right", you can see a camera shadow move across El Niño.
Revealing mistake: The scorpion Jimmy puts in the bag is obviously fake. It's arms and legs do not move at all, and it bobbles around like a rubber toy.
Continuity mistake: When Jimmy and War are fighting with the burning sticks, in several shots the sticks go from being on fire, to put out, to partially on fire, etc.
Continuity mistake: When Lily's brother threatens Jimmy with the gun towards the beginning, in the first shot he still has the flowers and ring in his hand, but in the next shot they are suddenly gone, and he is getting his gun.
Revealing mistake: While at the wedding chapel, a shot is fired off camera in the other room, and we see the flash of the gun light up much of the chapel. But gun flashes aren't big enough to emit such light.
Continuity mistake: When Jimmy rescues the young boy, in the first shot he under the side of the large cloth tarp, but suddenly about two shots later, he is in the center, without having time to get there.
Revealing mistake: When War blows himself up, you can see a reflective material inside of the burning "crow symbol" likely to help contain the fire.
Other mistake: Jimmy walks away from his trailer to find Lily quite a distance, yet when they sneak behind a building, you can see the graffiti the kids drew on the side of Jimmy's house right behind them, as though Jimmy has walked in a giant circle for no reason.
Continuity mistake: The position of the protesters changes in almost every shot in the very beginning.
Revealing mistake: Right after Luc Crash becomes Lucifer, he combs his hair, but you can see he just lightly runs the wrong side of the comb through his hair, as so not to mess it up.
Plot hole: Everyone considers Jimmy to be evil because he accidentally killed one of the Natives, who was trying to rape Lily. Yet, you see the ordeal and there are other witnesses, so it makes no sense that nobody believes him about not doing it on purpose, and unprovoked.
Continuity mistake: When Jimmy and Lily meet in the beginning, the people in the background change in some of the shots.
Deliberate mistake: When Luc Crash is attacking the guards at the beginning, once or twice one of his blows is repeated twice from different angles, and it does not appear to be for effect.
Revealing mistake: When Lilly's brother is firing at Luc and Lola, you can see the bullets hitting on the church behind them are too big and spark too much to be real, revealing squibs were used.
Deliberate mistake: You can tell the miner uniforms and prisoner uniforms are exactly the same wardrobe, the prisoner uniforms are simply marked "Prisoner" to make them seem different.
Continuity mistake: When Jimmy first awakens, after he crawls out of the water, his body is in a different position and much further away from the water in the next shot.
Continuity mistake: When Lily's brother gets into his car in the beginning, he turns his head away from Jimmy twice between cuts.
Continuity mistake: When Luc's cronies beat up Jimmy after he enters the store, in one shot War kicks him and then the camera cuts and he is suddenly helping Famine lift Jimmy.
Continuity mistake: When Jimmy meets Lola and Luc at Rave-N-Fest, the position of the hands Lola is eating grapes with changes between shots behind and shots facing her.
Other mistake: The junkyard at the mine is supposed to have materials just from the mine, yet there seems to be junk from all over town there, which doesn't make sense.
Answer: As I understand it, it all had to do with a spat between the director of the original Crow movie (Alex Proyas, who had "approval" of all the subsequent Crow movies) the producer of the Crow movie franchise, Jeff Most, and Miramax. Miramax eventually caved in favor of the producer and it was made into a "non-Crow entity" when Miramax reportedly signed Eminem to play the bad guy.