Breath Test

A man is driving down the road somewhat erratically. A cop notices this and pulls him over; he walks up to the window and says:

"Sir, I believe you're drunk. I'm going to administer a breathalyzer test"

Man, sheepishly: "Oh, I'm sorry officer, I'm a severe asthmatic, and I don't have my inhaler with me...if I blow into that thing I could have an attack and die"

Cop, a little distrustful: "Uh, yeah...well, this is more invasive, but if you won't submit to a breathalyzer, I'm going to have to take you down to the station and take blood"

Man: "Yeah, well, see, the thing is, I'm a terrible hemophiliac, and so I can't give blood...I might die"

Cop, clearly frustrated: "Alright buddy, well, this is imprecise, but I'm going to have to have you get out of your vehicle and walk this line heel-toe"

Man: "Oh, I'm sorry officer, I can't do that, I'm drunk."