"Son I just need you to do a quick breathalyzer test."
"I can't do that, officer, I have severe asthma. If I blow into that tube, I could risk an attack."
"Alright, then just come down to the station and we'll do a blood test."
"I can't do that either, I'm a hemophiliac. Any puncture will end up bleeding for hours then I'll pass out."
"Okay, then step out of the car and we'll do a standard field sobriety tes-"
"Sorry, but I have a slight vitamin b12 deficiency, so I naturally shake while doing basic tasks, so the tests would be inconclusive."
"Well then just walk along in a straight line."
"I can't do that either"
"Why?"
"Because I'm drunk."