The bus crash would not have happened as shown. The rod impacted the bus well behind the driver, so the driver would have been in control of the bus.
The instant explosion after the bus crash does not happen in car crashes. The explosions take place only if a fuel tank is nearly empty (vapors not fluid explode), and it takes being on fire for far longer than was shown.
Det. Dawson pulls up to the stabbing scene and jumps out of his truck, leaving it running. He then leaves in the ambulance, leaving one patrol officer with an unruly crowd. In reality, his truck would have been gone in 60 seconds.