A. It is a defense to any action brought pursuant to this Chapter that the person who possessed with the intent to distribute or distributed a controlled substance did so under the authority of law as a licensed physician or practitioner, as an ultimate user of the controlled substance pursuant to a lawful prescription, or as a person otherwise authorized by law.
B. A law enforcement officer or agency, the state, or any person acting at the direction of a law enforcement officer or agency or the state is not liable for participating in the marketing of an illegal controlled substance, if the participation is in furtherance of an official investigation.