Uber admitted in court filings today that it still uses commercially available LiDAR systems in its self-driving vehicles because its in-house technology isn’t ready for the road.

Acknowledging that its technology is second-best is a rare move for a competitive startup, but as Uber faces a lawsuit from Waymo, claiming the runner-up title might save its self-driving car program.

Uber is also claiming that, although one of its engineering leads is accused of stealing tens of thousands of secret documents from Google, those documents were never uploaded to an Uber-owned computer and therefore never used in the development of its LiDAR systems.

Waymo’s “frenzied race” against Uber to bring the first self-driving car to market came to a head in February when the Google-owned auto company filed a lawsuit against Uber, claiming the startup had misappropriated its trade secrets and patented information. Waymo claims its trade secrets were stolen by Anthony Levandowski, who allegedly downloaded 14,000 confidential documents from Waymo systems before launching the self-driving truck company Otto that was quickly acquired by Uber. (See a complete timeline of the case here.) Waymo is seeking a sweeping preliminary injunction against Uber that, if granted, could shut down its self-driving program while the case is underway.

“Waymo’s injunction motion is a misfire: there is no evidence that any of the 14,000 files in question ever touched Uber’s servers and Waymo’s assertion that our multi-lens LiDAR is the same as their single-lens LiDAR is clearly false. If Waymo genuinely thought that Uber was using its secrets, it would not have waited more than five months to seek an injunction. Waymo doesn’t meet the high bar for an injunction, which would stifle our independent innovation—probably Waymo’s goal in the first place,” Uber’s associate general counsel Angela Padilla said in a statement.

Uber can’t stop what never started

To keep its program alive, Uber has to convince the judge that it’s not using Waymo’s trade secrets or infringing its patents — so Uber admitted that it buys its LiDAR systems from third-party suppliers, including Velodyne, a supplier that also worked with Waymo before it developed its own system. Uber also claims that, contrary to paperwork filed with the Nevada DMV, it has never deployed a custom LiDAR system in any of its cars or trucks and will not be ready to do so by the time the case is slated to go to trial in October.

In other words, Uber says a judge can’t stop it from using the technology if it never started in the first place.

Uber is admittedly behind on self-driving tech. Google launched its self-driving car project in 2009 and spun it out as Waymo under its parent company Alphabet late last year. Uber, in contrast, has only been working on self-driving vehicles since 2015 when it poached talent from Carnegie Mellon to kickstart its effort.

That early work is important to Uber’s case because it demonstrates LiDAR development was underway at Uber’s Advanced Technologies Center in Pittsburgh before Levandowski arrived at the company. Uber says its LiDAR efforts were led by Scott Boehmke, a Carnegie Mellon expert on LiDAR and radar. Boehmke started working on Uber’s custom LiDAR in early 2015, before Uber acquired Otto in August 2016.

After the acquisition, LiDAR development accelerated and the project was given the code-name “Fuji.” Boehmke joined forces with James Haslim, who came to Otto during its acquisition of the Levandowski-linked company Tyto, and the pair developed Uber’s current system, which is still under development.

Uber says the LiDAR technology it’s developing is fundamentally different from what Waymo uses. Waymo prides itself on its single lens system, while Uber says its technology relies on four lenses. Uber also notes that its design has two optical cavities, while Waymo’s has only one.

“Waymo took one Uber schematic (inadvertently sent to a Waymo employee) and made several assumptions based on that one document to conclude that Uber’s LiDAR used a single-lens design. Waymo could not be more wrong, and Uber’s design could not be more different,” Uber argued.

But in paperwork filed with Nevada regulators last July, Otto claimed that it “developed in house and/or currently deployed” a 64-laser LiDAR system in its autonomous trucks. Uber now says this was an error. “Every single self-driving car that Uber has put on the road to date uses commercially available LiDAR sensors from third parties,” Uber wrote in its filing.

However, Waymo argued, “As is clear from the evidence, the LiDAR technology that Uber and Otto have ‘developed in house and/or currently deployed’ is in fact Waymo’s LiDAR technology.”

The mystery of the missing documents

Uber’s attorney Arturo Gonzalez told reporters on Thursday that he would show none of the 14,000 documents made their way to Uber. In court, he portrayed Levandowski as the most respected mind in the race to build self-driving vehicles and mentioned a self-driving motorcycle Levandowski built that is now enshrined in the Smithsonian.

“He set up two companies and did all that before he set foot on Google’s grounds. This is not someone who has to steal anything. He knows this stuff,” Gonzalez said.

“Then why did he steal this stuff? That’s the story the jury’s going to want to know about,” Judge William Alsup retorted.

But Uber is attempting to draw a bright line between itself and its accused employee, who — unless a preliminary injunction orders otherwise — is still leading Uber’s self-driving car unit. “Uber made sure to have policies and practices in place to prevent misappropriation, and these measures have worked,” Uber wrote in its filing.

A Waymo spokesperson countered, “Uber’s assertion that they’ve never touched the 14,000 stolen files is disingenuous at best, given their refusal to look in the most obvious place: the computers and devices owned by the head of their self-driving program. We’re asking the court to step in based on clear evidence that Uber is using, or plans to use, our trade secrets to develop their LiDAR technology, as seen in both circuit board blueprints and filings in the State of Nevada.”

The ride-hailing startup has questioned dozens of employees and searched several computers and servers for file hashes and keywords that might indicate Waymo’s intellectual property. So far, the hunt has turned up only one file — on the personal computer of an engineer who, like Levandowski, also formerly worked at Google. Uber claims the engineer, Sameer Kshirsagar, accessed the file and other Waymo documents while still employed at Google in order to prepare a transition memo for his supervisor about his departure.

Alsup ordered this week that the search should continue, with Waymo choosing 15 search terms and 10 employees who it wants searched.

Uber also claims that many of the details Waymo has described as secret aren’t secrets at all — in fact, Uber argues that they came from publicly available PhD research, patents and textbooks. One of the designs Waymo claimed as secret is reflected in a patent filed by Velodyne, Uber claims.

An injunction could be coming soon

Now that Uber has filed its opposition to the preliminary injunction, Judge Alsup could rule soon on whether or not Uber’s self-driving program should be allowed to continue with Levandowski at the wheel.

Waymo has asked for broad restrictions on Uber’s program: that Uber be forbidden from “accessing, using, imitating, copying, disclosing, or making available to any person or entity” Waymo’s trade secrets and from “making, using, selling, or offering to sell devices” based on Waymo’s patents. Waymo says that allowing Uber to continue its work would cause irreparable harm.

Uber, of course, is asking that no injunction be made. The company says Waymo waited months after its suspicions about Levandowski were first raised before it filed for an injunction, so it can wait a few more until the trial is complete.

“To hinder Uber’s continued progress in its independent development of an in-house LiDAR that is fundamentally different than Waymo’s, when Uber has not used any of Waymo’s trade secrets, would impede Uber’s efforts to remain a viable business, stifle the talent and ingenuity that are the primary drivers of this emerging industry, and risk delaying the implementation of technology that could prevent car accidents. Ultimately, that would be harmful to the public,” Uber wrote.