Alphabet, Waymo's parent corporation, believes those files include the secrets of its self-driving system, including its LiDAR technology that serves as its autonomous car's eyes to see the road, obstacles and pedestrians. Those files are now the center of its lawsuit against the embattled company, which recently lost its CEO following a succession of scandals.

"Prior to the filing of this lawsuit, no one at Uber knew that Levandowski had downloaded any Google proprietary information for any improper purpose or that he had deliberately taken any Google proprietary information with him when he left Google," the documents said.

Uber stressed that Levandowski didn't steal those files to ensure his employment at the firm. If you'll recall, the engineer founded his own autonomous truck driving startup Otto, which Uber snapped up for $680 million, after leaving Google and only joined the ride-hailing company as head of its self-driving operation after the acquisition. The filing said the engineer stole the files in order to ensure that Google pays him the $120 million bonus it promised him.

As expected, Waymo's filing insisted that Uber and its former engineer hatched the devious plan together. It said the fact that Levandowski told ex-Uber chief Travis Kalanick that he still has discs containing Google information at a March 2016 meeting proves that the company knew about the theft. Plus, it said it was unable to access text messages from Kalanick to the engineer during discovery, suggesting that they were deleted. The ride-hailing service parried that by saying that the engineer reported destroying the discs after Kalanick told him he didn't want the info.

If Uber wants to come out on top after the trial scheduled in October, its arguments must be extra convincing. Waymo's already a step ahead: in May, US District Judge William Alsup said Alphabet made a compelling case that the engineer took off with its secrets and that Uber knew that from the start.