Continuity mistake: When the main character goes to visit his friend that had been shot in Iraq, they're driving down a country road in a 2 door Dodge Challenger, but when inside the vehicle it's a Dodge Charger, which is a four door car.
Continuity mistake: When Megan is outside the supermarket asking people to sign her petition, a woman walks up and begins writing on the clipboard. In the first shot, the cap is on the back side of the pen. From the next angle, the woman is scribbling and lifts the pen to show the cap covering the tip that she was "writing" with.
Continuity mistake: He drinks from a water bottle and finishes it. The next cut it's got water left in it. (00:22:00)