Continuity mistake: The gas station scene where Kliner Jr. is leaning against Roscoe's truck. It starts as the passenger side, then cuts to him moving away, and she enters the drivers' side.
Continuity mistake: A woman approaches Oscar Finlay when he's having a beer at the bar. She asks him "What do you do?" and his hand is at the bottom of the glass, only to be at the top of the glass in the reverse shot. It happens again as the two different angles alternate. (00:36:05)
Answer: As Reacher had arrived in town just after the murder occurred and being a stranger, he became a suspect (or at least a person of interest) and taken into custody for questioning by the police. He was released fairly quickly. It was coincidental timing of an outsider arriving at the same time as the crime occurred.