Plot hole: Shortly before the penultimate fight between Feathers and UB, Smart Brother comments that UB has a few seconds before the reactor goes. Yet, no matter how loosely SB's words are interpreted, the whole sequence from when he said that to when it blew lasted longer than "a few seconds".
Visible crew/equipment: Throughout this entire movie, it is possible to see the sound recording equipment above. (00:58:55)
Revealing mistake: Just after the B.R.O.T.H.E.R.H.O.O.D. discover who UB is, it cuts to UB in his apartment, apparently having a kung-fu moment. As he jumps backwards into the wall, it wobbles quite badly (as do the parts mounted to it) - obviously just a piece of free-standing plasterboard. (00:09:25)
Audio problem: When UB is running through the things that have been done by "The Man", in the Chief's office (ie. NBA 3-point shot, Spike Lee), after UB says "So the entertainment industry really is out to get Spike Lee", he says "Is that right?" but if you watch UB's mouth, he is not saying this line.
Revealing mistake: When the white guy is smashing one of the bad guys' head and green blood is coming down, you can see the pipes that shoot it into the head.
Continuity mistake: In the scene where UCB first arrives at "The Brotherhood" the medallion he is wearing changes three times: a lion fang, a small gold disc, and finally when Chubby Brother is showing UCB the modifications to his car the large disc with the fist raised that his father gave him.
Continuity mistake: In the scene where Lance is checking the B.R.O.T.H.E.R.H.O.O.D.'s boss' blood pressure, the cuff is on the boss' arm, then after a quick shot away to someone else the cuff is off his arm, too quickly as the boss and Lance don't appear to have moved.