When the camera takes a picture at a red light, the photos are reviewed by a police officer (or, in some states, two) before they are mailed. Generally, one of the officers will need to show up at trial
to explain the picture to the court, explain that the camera is reliable, and tell when it was last serviced to establish accuracy. Due process entitles a person who is accused of committing a crime to have the state prove that.
Entrapment occurs when the state does something that induces an ordinarily law-abiding citizen to break the law. Entrapment requires more on the part of the state than the placement of cameras and requires that the person accused is someone who would not have broken the law without the state's interference. In this situation, an entrapment defense would require that a police officer induced your boyfriend to drive an unsafe speed such that it was impossible for him to stop for the yellow light.
Regarding the DA, I absolutely agree that the state made a mistake. However, unfortunately, a scheduling error will not entitled a person to have the underlying ticket dropped. The DA has a duty to correct the mistake, recall the warrant, and make sure there are no additional negative consequences, but does not have to dismiss the original ticket.
I apologize if that's not what you were hoping to hear. Sometimes, the law just isn't on our side.