I saw this comment on the houston chronicle website commenting on the charge that killed the 2 people mentioned in the OP and wanted to QFT:
"The charge of Intoxicated Manslaughter is kind of like saying, "OOPS!" If Petty had chosen a gun instead of a car and walked down the Gulf Freeway occasionally firing the gun and two people had been killed, would the charge still be Intoxicated Manslaughter ? No, it would be murder, possibly capital murder. The choice of weapon should make no difference. The charge should be murder.
I would like to see Intoxicated Manslaughter removed from the books and treat this kind of crime as any other homicide would be treated. It was not an accident; it was a choice, made before he ever took the first drink. He chose not to have a designated driver. He did not arrange for safe transportation. He chose to drink. "
- VetMom