Any person claiming ownership of any money or property sought to be reached in the possession or under the control of the garnishee as the property of the defendant in the original action may intervene in the garnishment proceedings by a suitable pleading and set up facts showing that the debt or the property with which it is sought to charge the garnishee is the property of such intervenor. The defendant in the original action may by a suitable pleading filed in the garnishment proceedings set up facts showing that the debt or the property with which it is sought to charge the garnishee is
(1) exempt from execution, or
(2) for any other reason is not liable for plaintiff's claim. If issue on such intervention or on such pleading by the defendant in the original action is joined by the plaintiff, it shall be tried with the issues as to the garnishee's liability. If such debt or property or any part thereof is found to be the property of the intervenor, or is found to be exempt or not liable, the garnishee shall be discharged as to that part which is exempt or not liable.