This common explanation always seemed like BS to me. What seems more likely is that in many drunk driving crashes the drunk driver crosses the center line or runs a red light and impacts the side of another vehicle. So the people who are hit from the side may be killed while the drunk driver is partially protected by the mass of his own engine.
This particular case may be different but the article did say that the driver of the police car is in critical condition.
One other thing is that the dangerous driver has his hands on the wheel, and can hold on a bit. I know when there is jostling, the passenger is tossed around a lot more.