Factual error: When Reacher sees Sandy's body being loaded into the coroner's van, he's able to see her face. In reality, a dead body is zipped into a leak proof body bag for transport. And that body is put in the bag and zipped up WHERE THEY DIED, not in the van or somewhere else. Specifically, this was a murder scene and any evidence and DNA would have been secured on the body by the body bag.
Factual error: At the shooting range when Reacher hangs his target, you can see it's either AS500 or something softer because of the damage. When Reacher fires his shots go clean through the target without any spalling damage done to the paper.