premise: but uh they say that there it's almost down to zero where people come back and say they are positive and and they're not you know in other words there's very few mistakes and that of course has got to be critical it's got to be if you have a drug testing program it's got to be with a very very good agency you don't just have you know some local uh group do it it's got to be a a a highly qualified agency
hypothesis: Some local drug testing groups always have errors in their tests.