Revealing mistake: In the scene where Sarah crashes into the agent's buggy, you see they have been replaced with dummies. When the car first hits, you see one of the dummies fall out, but they are both seated in the next shot. Also you see that it is not Sarah driving but a man. (00:36:50)
Revealing mistake: When Sara crashes into the ATV to save Michael, you can see that the people on the ATV are switched out with crash-dummies.
Going Under - S4-E15
Revealing mistake: Sucre and Linc are driving to the pier and there is a shot looking at their SUV. In the background you can see a cop directing traffic away from the shot. It's fairly obvious.
Answer: Because of coincidence.