Colorado Revised Statutes Title 18. Criminal Code § 18-8-509. Perjury and false swearing--irregularities no defense

(a) The defendant was not competent, for reasons other than mental disability or immaturity, to make the false statement alleged;

(b) The statement was inadmissible under the law of evidence;

(c) The oath was administered or taken in an irregular manner; or

(d) The person administering the oath lacked authority to do so, if the taking of the oath was required by law.