Google’s legal battle with Uber over the development of self-driving cars is already off to an ugly start. Lawyers for the two tech firms spent the last two days bickering over which attorneys should be allowed to view the trade secrets Google claims were stolen by their former employees who went to work at Uber, and a lawyer for Uber said today in court that the company has been unable to locate one of those engineers.

Google’s self-driving car unit is taking Uber to court over allegations that a star figure in the development of automated vehicles, Anthony Levandowski, stole trade secrets from Google before he abruptly quit his job. Soon thereafter, he founded his own self-driving truck company, Otto, which was acquired by Uber for $680 million.

Waymo, the self-driving wing of Google’s parent company Alphabet, claims that Levandowski downloaded 14,000 sensitive documents from a secure repository just before quitting without notice in January 2016. The company has also accused two other engineers, Radu Raduta and Sameer Kshirsagar, of swiping a handful of documents before they also accepted jobs at Uber.

Raduta doesn’t work for Uber anymore, Uber’s attorney Arturo Gonzalez told the court, and Uber hasn’t been able to locate him. Waymo claims that Raduta, who worked as a mechanical engineer for the company, downloaded several documents related to the self-driving car project last July, just before going to work at Uber.

Gonzalez told reporters that Uber plans to argue in upcoming filings that the “whole matter” belongs in arbitration between Google and Levandowski, citing Levandowski’s contract with his former employer.

Uber also pushed back against Waymo’s claims that none of Uber’s in-house lawyers should be allowed to see unredacted versions of court filings that contain Google trade secrets. The two companies eventually settled on an agreement that just one of Uber’s in-house lawyers, Nicole Bartow, would be allowed to view the documents.