Then the argument is over what constitutes existing evidence. If your breath contains an undue percentage of alcohol, that’s evidence - which exists, the breathalyzer simply acquires & quantifies it. We’d have to objectively define a limit to such acquisition (sticking device in one’s mouth, vs sampling air inches away).
that is not the test the court addressed. The court said forcing a suspect to take a deeper breath than normal was beyond the mere presense (plain sight) test.
The machine requires the subject to force air into the machine.