Factual error: After mounting armor in the bus they are approaching Phoenix on a two lane highway from the northwest. When entering the city they are shown coming around South Mountain on Interstate 10 from Tucson from the south.
Audio problem: After the bus crashes to a halt on the courthouse steps, the gunfire stops. A few seconds later, a bullet hole opens up on the side of the bus - but there is no sound.
Continuity mistake: When Ben, Gus and the hijacked cop stop at gas station to use pay phone, the vehicle next to the phone is a Toyota Land Cruiser. Seconds later in the phone booth, the vehicle is a Suburban.