In what circumstances will a husband be allowed to add a supplemental complaint to his wife's personal injury action?

In Groom v. Bangs, 153 Cal. 456, 96 P. 503, the plaintiffs, husband and wife, joined in an action for the wife's personal injuries. She died, and the plaintiff husband, with leave of court, filed an amended and supplemental complaint for wrongful death of the wife. The court referred to the procedure as 'irregular,' but upheld it as no objection had been made in the trial court. The case is of value here because the court, in effect, held that the 'irregular' filing of a supplemental complaint was not jurisdictional.