Other mistake: JJ says that everybody else in the office just has to look at their watch when the boss asks them the time but he has to go outside down the block because he can't afford a watch. Throughout the whole scene, you can see a wristwatch on his right wrist. He even raises his arm where his sleeve moves to his elbow to show it. It looks like a pretty expensive watch too. (00:05:00)
Visible crew/equipment: After JJ gives Michael his little black book, Penny spots Boom-Boom's numbers. When Willona walks over and sits on the back of the couch, her mic transmitter wires are hanging out the bottom of her sweater behind her. Then, when JJ doubles over in pain, the bulge of Willona's mic transmitter is visible at her lower back. (00:04:15)
Answer: Could have very well been that he did have a speaking part, but ended up on the cutting room floor, and they just didn't fix the credits.
ckbyers