(a) An exception to an offense in this title is so labeled by the phrase: “It is an exception to the application of …,” or words of similar import.
(b)
(1) Unless the statute defining an offense states to the contrary, the state need not negate the existence of an exception in the charge alleging commission of the offense.
(2) An exception to be relied upon by a person must be proven by a preponderance of the evidence.