Visible crew/equipment: The cameraman is visible in the reflection of window while Holden is walking back to his car in the rain.
Revealing mistake: When Holden is driving his Ford explorer, the speedometer reads that he's going 0 mph. (00:50:35)
Continuity mistake: When Silent Bob is telling the Amy story in the diner, his cigarette mysteriously grows from barely above the filter to about half length, then it disappears from his hand entirely, and he draws a new one. (01:30:40)
Continuity mistake: During the hockey fight, number 12's helmet is off, then on, then off again. (01:17:00)
Continuity mistake: Towards the end where Silent Bob is in the diner, he finishes reading a comic book and they show him toss it on the table. However, in the very next shot from a different angle he has the comic book in his hand again and tosses it on the table once more. (01:25:15)
Other mistake: Right after Cohee tells us the story of how Alyssa got the nickname "Finger Cuffs", after the shot returns to Banky and Holden, there's one frame with a significant 'burn mark' on the right side of the negative. Pronounced enough even to be noticeable at regular viewing speed. (01:10:30)
Continuity mistake: At the end, when the fan at the convention gives the last issue of Bluntman And Chronic to Banky to sign, Banky looks through the book with his pen in his left hand. It cuts away, and then back again, and the pen is in his right hand. (01:44:20)
Continuity mistake: During the dart scene, the customers who use the restrooms ignore the gender signs. (Most likely intentional, but worth a look). (00:14:20)