Character mistake: The interviewer pointed out that Evan [Mark Wahlberg] is a "smart guy" and another man later said, "Homeboy knows everything. He's a freak." When Evan was telling the interviewer the circumstances under which he assaulted a man, Evan committed a basic grammatical error - a misplaced modifier: "I asked him to leave politely." Evan didn't mean he wanted the man to leave in a "polite manner"; he meant he "politely asked" the man to leave. (00:09:20 - 00:14:00)
Character mistake: Evan's response to "What's gunpowder made of?" was "74% potassium nitrate, 13% charcoal." A "smart man" who "knows everything" should realise that the two total 87% and there's a third ingredient (surfur) needed to comprise the remaining 13%. Gunpowder does not have a single "recipe", so the % of the 3 ingredients can vary. Generally, 75% potassium nitrate (or "salt peter"), 15% charcoal, and 10% sulfur may translate to 74.8%/13.3%/11.9% respectively. The 74.8% should be rounded up, not down? (00:14:00)
Character mistake: When Toby said, "Cops found a sword on him [Evan]", he pronounced the "w" in sword, but it is a silent "w" (not pronounced). Sword is correctly pronounced like "sord" or "soared." (00:18:28)