NRS 200.430

Any person who is present at the time of fighting any duel with deadly weapons, as second, aid, surgeon or spectator, or who advises or gives assistance to such a duel, is a competent witness against any person offending against any of the provisions of NRS 200.410 and may be compelled to appear and give evidence before any justice of the peace, grand jury or court, in the same manner as other witnesses; but the testimony so given may not be used in any prosecution or proceeding, civil or criminal, against the person so testifying.