This chapter does not limit the introduction of any other competent evidence bearing on the question of whether the person was under the influence of intoxicating liquor, drugs, or a combination thereof, but, if the chemical test results show a drug or an alcohol concentration of at least ten one-hundredths of one percent, the purpose of the evidence must be limited to the issues of probable cause, whether an arrest was made prior to the administering of the test, and the validity of the test results.
N.D.C.C. § 39-24.1-10