Hahn

BACKGROUND

A.

Section 474 allows a plaintiff who is ignorant of a defendant’s identity to commence suit—before the statute of limitations runs—by using a fictitious name for that defendant and then amending her complaint when the defendant’s true name is discovered. (Austin v. Massachusetts Bonding & Insurance Co. (1961) 56 Cal.2d 596, 602-603; accord, § 474.) If the statute’s requirements are satisfied, the amendment relates back and the substituted defendant is considered to have been a party from the action’s start. (McClatchy v. Coblentz, Patch, Duffy & Bass, LLP (2016) 247 Cal.App.4th 368, 371 (McClatchy).)

B.

In 2015, Richard Hahn and Susan Hahn (a plaintiff here) filed a personal injury/loss of consortium action (Hahn I) in which they alleged that Richard Hahn’s mesothelioma was caused, at least in part, by exposure to asbestos at his job with the San Francisco Municipal Transportation Agency (the Agency).

Air Brake was never named as a defendant in Hahn I. However, Richard and Susan Hahn’s counsel took the deposition of Michael Ellis, in October 2015, who was designated as the Agency’s person most knowledgeable on brake components used in its light rail vehicles. In…