The Supreme Court's opinion in Branick v. Downey Sav. & Loan Association, ___ Cal.4th ___ (2006), is even shorter than its opinion in Mervyn's. The Court rejected the defendants' argument that permitting amendment would "contradict the policy objectives underlying Proposition 64":
The argument is not convincing. The policy objectives underlying Proposition 64 are fully achieved by applying the measure to pending cases, as we have concluded it must be applied. (See CDR [v. Mervyn's], supra, __ Cal.4th __.) An additional rule barring amendments to comply with Proposition 64 does not rationally further any goal the voters articulated. .... Proposition 64 does not expressly or implicitly forbid the amendment of complaints to substitute new plaintiffs ....
(Slip op. at 5 (emphasis in original).) The Court then turned to "the question ... whether the plaintiffs in this case may amend. Code of Civil Procedure section 473 states the governing rule." (Id. at 6 (emphasis in original.) Under the ordinary rules governing amendment to complaints (as set forth in Code of Civil Procedure section 473), the trial court should determine in the first instance whether leave to amend should be granted:
Because the voters adopted Proposition 64 while this case was on appeal, plaintiffs have had no opportunity to file a motion in the superior court for leave to amend. We thus do not know the facts that would necessarily inform the superior court’s discretionary decision on such a motion, such as the identity of any person plaintiffs might attempt to substitute and the nature of the claims any substituted plaintiff might assert. For this reason, and because the decision properly belongs to the superior court in the first instance (Haley v. Dow Lewis Motors, Inc., supra, 72 Cal.App.4th 497, 506), the Court of Appeal correctly concluded the matter must be remanded to the superior court to determine whether, if plaintiffs do move to amend their complaint, the circumstances of this case warrant granting leave to amend.
(Slip op. at 7.) Finally, the Court rejected several defense arguments as either wrong or premature:
(Slip op. at 7-8.) This is a very measured decision that takes great pains not to decide any issue not squarely presented.
Defendants argue plaintiffs should not be permitted to substitute a new plaintiff because their failure to name the new plaintiff in their original complaint was not a mistake. No such rule exists. To the contrary, courts have permitted plaintiffs who have been determined to lack standing, or who have lost standing after the complaint was filed, to substitute as plaintiffs the true real parties in interest. [Citations.] Amendments for this purpose are liberally allowed.
The important limitation on the rule just mentioned is that the plaintiff proposed to be substituted may not “state facts which give rise to a wholly distinct and different legal obligation against the defendant.” .... Given the question’s potential factual and legal complexity, and without knowing the identity of the hypothetical new plaintiff or the nature of the claims he or she might assert, for this court to attempt to decide at this stage of the proceedings whether any possible amendment would impermissibly change the nature of the action would be inappropriate.