But you've already commissioned what is the actual crime - operating a motor vehicle in a condition that renders you unsafe to do so. If you kill someone in a car accident where you weren't drunk, and otherwise didn't break any road rules or fail to drive safely, you won't be charged with manslaughter. It's the driving when intoxicated that is the real crime. In that state, whether or not you kill someone becomes a lottery. Given it's such an easy risk to avoid, and given the consequences are so extremely dire, I think anyone who is that careless to have the "one extra sip" (which is BS anyway, one "sip" is not going to make a measurable difference and even if it does, will be gone by the time they do the confirmatory blood test - you'd be well and truly over at the time of the breath analysis to still be over by then), deserves to have the book thrown at them.
You're essentially putting a single bullet in a revolver, spinning the chamber, and then firing it at someone - most of the time it won't actually shoot them, but it's such an unspeakably stupid thing to do that it is rightly considered a criminal offence. It's just carelessness bourne of not admitting responsibility for your actions to fail to adhere to these laws.
Saying punish them like they've committed manslaughter is probably hyperbole. But, if I had my way, not by much. True to say that if I had my way, the driving population in Australia would probably be about halved in short order, and we would need new jails. I think you deserve a criminal record and lifetime driving ban if you drink drive. I think if you've been disqualified from driving and are caught driving, you should go to jail for two years, and your car to be seized and sold. I'd make licence testing a hell of a lot harder, and make drivers retake the test every five years. I'd get rid of financial penalties for speeding, but at least double the points you incur if caught, with a 10 year ban from driving being the result for licence disqualification for reasons of speeding.
Putting someone behind the wheel is the most common way we empower people to kill themselves and others. If we proposed allowing every 18 year old who could pass a multiple choice quiz and drive around a deserted suburban block to then walk around carrying a loaded gun, there would be uproar (unless we were Americans
). Sorry to rant, it's just a subject I reckon we're still massively immature about, and I'm kinda sick of nearly being killed once a week by morons driving like they're playing Daytona at the arcade.