In the scene where the guy on the couch tosses the crumpled piece of notebook paper to Thurgood, as Thurgood is reading the note it is evident that the guy spelled sincerely wrong. He failed to include the second "e".
When Brian, Kenny, Scarface, and Thurgood are in a convenience store in the beginning of the movie, Brian is holding his head, asking everybody if they're OK. When we hear him say, "How you doing. Kenny?", his mouth doesn't move.
In the theater version, a boom operator, complete with mike, could be plainly seen crouching in the corner after Mary Jane slams her apartment door in Thurgood's face, and he tries to talk to her through the door. The crewman is directly behind Mary Jane's door, inside her apartment. Later, in the home-video version, this mistake was corrected, but the top of the crewman's head is still visible at the bottom of the screen.
When Thurgood takes Mary Jane on a date, she suggests they go for Chinese food and we see a shot of the restaurant sign. The movie takes place in New York, but the sign says "Licensed under LLBO", which is the Liquor Licensing Board of Ontario.
Brian, Scarface and Thurgood hand out the samples at the club and after it is apparent that all were smoked, one of the "floating" people is swimming. You can see the wire harness on the back of his hip moving him along.
Dave Chappelle played Thurgood Jenkins and Sir Smoke A Lot. So when Thurgood went to Sir Smoke a lot's house, it was another actor playing Sir Smoke a lot when Chappelle was playing Thurgood and Vice-versa. When you see Thurgood first he has a earring in his ear. But when Sir Smoke a lot hugs him, the actor playing Thurgood has no earring in.
Mary Jane meets Thurgood, Scareface and Brian at the prison. When the three of them are sitting in Mary Jane's Jeep, before Mary Jane gets in the ignition sound (sound when keys are left in ignition when car is off) can be heard, yet her door is not open and her keys are in her hand when she gets in.