Oh, that I did not know Frank. Very silly.
It's a very old law, and based upon ancient English common law.
Once in a while somebody gets up in a dander and wants to change it, but it probably won't be changed.
Usually what happens is that a physician will tell the county attorney, for example, "He died of a heart attack," and the county attorney, not having medical expertise, takes his word for it.
But the county attorney is the final word.