Other mistake: When the guys find out that they've passed the THC test, Jamal turns to Silas and asks if they're still high on the ivory. At the moment he asks, an elf walks across the room. This is supposed to be a figment of their imagination as they are high, so why does the woman at the desk watch the elf too?
Factual error: In the scene after Method Man cremates Ivory, the one where Method Man wakes up and goes to check on his plants, the weed on the Ivory plant is already trimmed, and dried. Method Man could've done this to the buds, but he reacts to it's potency like he has never seen it before.