However, the doctrine of defensive non-mutual collateral estoppel may bar plaintiffs from asserting a claim that they previously litigated and lost against a different defendant. See, e.g., Sahlberg v. P.S.C. Inc., 626 Fed.Appx. 719, 721-22 (9th Cir. 2015); LaRoche v. Smith, No. C15-1003-TSZ, 2016 WL 1221658, at *2 (W.D. Wash. Mar. 19, 2016). Washington courts “apply nonmutual collateral estoppel so long as the party against whom preclusion is sought was a party or in privity with a party to the prior litigation and had a full and fair opportunity to litigate the issue in question.”

See Order (docket no. 30 in C13-1913 TSZ). Plaintiff is bound by this earlier ruling even though Smith and Villacin were not parties to the malpractice litigation between plaintiff and Billbe. See Sahlberg v. P.S.C. Inc., 626 Fed. App'x 719 (9th Cir. 2015) (applying Washington law); Gausvik v. Perez, 396 F. Supp. 2d 1173, 1175 (E.D. Wash. 2005) (Washington and federal law concerning non-mutual collateral estoppel is not materially different). To the extent plaintiff asserts Smith and Villacin colluded with Hoffman, Kimball, and/or Billbe to omit at trial evidence favorable to plaintiff, see Pla.'s Mot. Summ. J. at 14 (docket no. 154), such claim defies logic.

That contention, if true, could also bar Plaintiffs' claims against the other Defendants under the doctrine of nonmutual collateral estoppel. See, e.g., Sahlberg v. P.S.C. Inc., 626 Fed.Appx. 719, 721-22 (9th Cir. 2015); LaRoche v. Smith, C15-1003-TSZ, 2016 WL 1221658, at *2 (W.D. Wash. Mar. 19, 2016).

While we agree that "if the district court considers matters outside of the pleadings, this court reviews the dismissal order as though it were an order granting summary judgment," Witherow v. State, Bd. of Parole Comm'rs, 123 Nev. 305, 307-08, 167 P.3d 408, 409 (2007), we decline to extend this rule to dismissal of a complaint as void ab initio under NRS 41A.071. Because a complaint found to be void ab initio "does not legally exist," Washoe Med., 122 Nev. at 1304, 148 P.3d at 794, a court cannot enter summary judgment on that complaint, see Sahlberg v. P.S.C. Inc., 626 Fed. App'x 719, 722 (9th Cir. 2015) ("Summary judgment is a final judgment on the merits"). As a preliminary matter, the court erred in permitting Dr. Hashim's deposition at the pleading stage of the proceedings, and then in considering his testimony as a basis for granting dismissal under NRS 41A.071.