(a) Except as provided by Subsection (b), all testimony taken in open court on the hearing of an application to probate a will must be:
(1) committed to writing at the time the testimony is taken;
(2) subscribed and sworn to in open court by the witness; and
(3) filed by the clerk.
(b) In a contested case, the court, on the agreement of the parties or, if there is no agreement, on the court's own motion, may waive the requirements of Subsection (a).