Revealing mistake: When Holden is driving his Ford explorer, the speedometer reads that he's going 0 mph. (00:50:35)
Continuity mistake: During the hockey fight, number 12's helmet is off, then on, then off again. (01:17:00)
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)
Answer: That is Matt Wagnerm, creator of the "Madman" comic series.