I had to Google the case you’re talking about. There are two massive differences in the cases: 1. The cop didn’t kill one person / cause grievous bodily harm to another and 2. The cop didn’t provide hours of dashcam footage showing erratic driving, speeding and driving dangerously.

Still that cop case is pretty bad. He left the scene and managed not to be breathalysed. So, there is even less evidence in his case. A drink-driving conviction, fine and community service is pretty much what everyone else gets for a first offense under the influence.