It’s up to the police to prove you were drunk while driving.

Actually, its up to the prosecution to prove you were drunk while driving. And that standard is ‘beyond a reasonable doubt’, which I’m pretty sure ‘pounding liquor after an accident to have plausible deniability on your insobriety’ would make an easy argument to meet that threshold.

The cops will take you either way and let a judge decide what to do with you.