One Liberty Place | 1650 Market Street | Suite 2900 | Philadelphia, PA 19103 (215) 680-8136

ESI Custodians & Proportional Discovery: Court Adds Elon Musk and Requires Cooperative Validation in Tesla Case

In Robert Matsko v. Tesla, Inc., No. 22-CV-05240-RFL (DMR), 2025 WL 1144827 (N.D. Cal. Apr. 18, 2025), Magistrate Judge Donna M. Ryu addressed a discovery dispute centered on identifying appropriate custodians and sources of electronically stored information (ESI) in a putative class action alleging fraud related to Tesla’s self-driving features. While the court agreed that documents should be collected from five previously identified custodians, it expanded the scope to include Elon Musk and a Tesla senior director based on a sufficient showing of their likely possession of relevant information. However, the court declined to require production from three other proposed custodians, finding the plaintiff had not demonstrated that those individuals held responsive materials.

The court also delved into the boundaries of proportional and defensible discovery under Rule 26(b)(1). While allowing the plaintiff, LoSavio, to obtain responsive emails from Tesla’s designated custodians, Judge Ryu declined to compel production of other forms of electronic communications, such as text messages, until the parties had met and conferred about the feasibility and proportionality of such searches. The ruling underscored the importance of collaboration in ESI protocol development and reinforced that expanding into additional communication platforms requires concrete justification tied to relevance and burden.

Finally, the court denied LoSavio’s unilateral proposal that Tesla be ordered to run his preferred search terms. Instead, the court directed the parties to negotiate mutually acceptable search parameters and, if unsuccessful, to present evidence showing how their positions aligned with proportionality standards. For Tesla, that meant demonstrating non-responsiveness through defensible validation practices, including “quality control measures such as sampling.” The decision highlights judicial emphasis on cooperation, transparency, and data validation in modern eDiscovery—ensuring that search methodologies and custodial scopes are both targeted and defensible throughout complex data-driven litigation.

If your organization is seeking support with eDiscovery, our team has solutions to address all phases of the discovery process. At CODISCOVR, we deliver client-focused, defensible, and scalable solutions using advanced technology and intelligent review practices to meet eDiscovery, document review, and information governance needs in a manner that reduces the risks and costs associated with electronically stored information (ESI). Reach out to Shari Coltoff at CODISCOVR for more information. Shari has over 20 years of experience in the ever-evolving eDiscovery life cycle, from document collection to managing large long-term reviews through productions.