A. It is no defense to a prosecution under this chapter that:
1. The statement was inadmissible under the rules of evidence; or
2. The oath or affirmation was taken or administered in an irregular manner; or
3. The defendant mistakenly believed the false statement to be immaterial.
B. The provisions of law which declare that evidence obtained upon examination of a person as a witness cannot be received against him in a criminal proceeding do not forbid giving such evidence against the person upon any proceedings founded upon a charge of perjury committed in such examination.