Rule 21.06 - Use of DepositionSubd. 1.Unavailability of Witness. A part or all of a deposition may be used as substantive evidence at the trial or hearing to the extent it would be otherwise admissible under the rules of evidence if: (a) the witness is dead or unable to be present or to testify at the trial or hearing because of a physical or mental illness or infirmity; or(b) the party offering the deposition has been unable to obtain the attendance of the witness by subpoena, order of court, or other reasonable means.Subd. 2.Inconsistent Testimony. A deposition may be used as substantive evidence at the trial or hearing to the extent it would be otherwise admissible under the rules of evidence if the witness: (a) testifies inconsistently with the deposition; or(b) persists in refusing to testify despite a court order to do so.Subd. 3.Impeachment. Any deposition may also be used by any party to contradict or impeach the deponent's testimony as a witness. A deposition may not be used if it appears that the party offering the deposition caused the deposed witness's absence, unless part of the deposition has previously been offered by another party.