Your friend is a dumbass, the blood tests will confirm or negate whether or not he was under the influence of a narcotic while driving. If he was then it's bye bye licence and low insurance rates.
I love how this is a fuck the police situation. Ya fuck those police for doing their job, fuck them because you don't agree. Jesus christ.
Your friend, as a young offender MUST have been immediately informed of his charge and his rights which INCLUDE the right to immediately contact an adult and/or lawyer. If he was not allowed to do so this charge will be thrown out immediately if the officer cannot prove why he did not afford this right.
I'm not familiar with american law. So you can be detained and tested without being arrested or charged?
Either way as a young offender you can't really do shit without having a parent/guardian/lawyer present....