Court of Appeals of Arizona August 5, 2010, 1 CA-CV 09-0106 (Preston v. Kindred Hospitals West, L.L.C.)

OPINION

DOWNIE, Judge.

¶ 1 This ease involves interpretation of Rule 17(a) of the Arizona Rules of Civil Procedure (“Rule”). We hold that plaintiffs/appellants should have been allowed to join or substitute the bankruptcy trustee as the real party in interest, without establishing that the proper party plaintiff was difficult to determine or that they made an “understandable mistake” by not