Breath tests are notoriously unreliable/inaccurate, to such a degree that in some jurisdictions the law is now phrased entirely in terms of a machine reading since it's been established there's no reliable relationship between the machine reading and blood alcohol level.
Seriously, read up on the history of breath-test machines sometime. Everything from difficult chemistry to literal "oops we misplaced a decimal point in the software".
Seriously, read up on the history of breath-test machines sometime. Everything from difficult chemistry to literal "oops we misplaced a decimal point in the software".