Other mistake: When Preston's dad starts to back out of the driveway, he abruptly stops to avoid hitting the moving truck, as if it had just recently appeared there. But they've been there for a while. As soon as he stops, he gets out of the car to start complaining, and the truck driver has already been out of the car for a significant amount of time.
Other mistake: During the park chase, Preston swipes the backpack from the person that picks it up, and is still being chased by Quigly. He somehow manages to put the backpack on in a span of about 7 seconds. Considering he is pedaling for his life, and the fear of the men catching him, it's unreasonable to assume that he could have done such a feat so quickly.