You can make a SC Public records request but you may not get something useful. They likely don't necessarily have the information you are looking for. I've been involved with several 911 dispatch systems over the years, and why we record the caller ID, sometimes the caller's name, and the location, we wouldn't have the name of victims or the vehicle ID. The police might have it if the accident was severe enough to make a report or EMS if the people were treated/transported. However, there are some exemptions to the PR act that would likely apply here.
But if you got the information or not, so what?
What obligation does he have to prove to you he was telling the truth. Whether he is telling the truth or not, or you can verify it or not, is largely immaterial to whether you can take job action against him or not (that involves information you haven't presented).