A traffic accident occurs and paramedics respond. However, one of the victims is pretty bad off and they transport him not to the nearest emergency room but to the best--and this is against explicit orders. This badly injured man does survive, but his daughter who seemed much less badly injured died...at the closer emergency room. When Quincy gets involved, he is ready to go off on a crusade--to change the rules and get victims to the best possible emergency room. The 'Golden Hour' reference is referring to getting the best treatment within the first hour of the accident, as you'll either save or lose most folks during this period.
What this episode could have really used was a crime. Let me explain. The best "Quincy" episodes seem to be ones where there is a crime to be investigated and the worst are often the ones that are social issues shows. In this one, the social issue are the rules that govern how paramedics respond to emergencies. And, not surprisingly, the show is weak and full of Quincy grandstanding and arguing. Preachy "Quincy" episodes spend more time promoting an issue than trying to entertain the audience. Overall, a rather dull episode. While I might not say it's among the show's worst (like the other reviewer says), but I certainly agree that it is not a particularly good one.