If a petition in a testacy proceeding is unopposed, the court may order probate or intestacy on the strength of the pleadings if satisfied that the conditions of AS 13.16.180 have been met, or conduct a hearing in open court and require proof of the matters necessary to support the order sought. If evidence concerning execution of the will is necessary, the affidavit or testimony of one of any attesting witnesses to the instrument is sufficient. If the affidavit or testimony of an attesting witness is not available, execution of the will may be proved by other evidence or affidavit.