SAN FRANCISCO (AP) — Former Uber CEO Travis Kalanick took the witness stand Tuesday, offering his initial response to allegations that he cooked up a scheme to steal self-driving car technology from Google.

Kalanick’s testimony centered on his dealings with Anthony Levandowski, a former star engineer at Google who left its robotic-vehicle project in January 2016.

Among other things, Waymo alleges that Kalanick and Levandowski conspired to use Otto as a storehouse of Google’s trade secrets in order to give them to Uber.

Kalanick sought to dispel those accusations while frequently sipping from a bottle of water during Waymo’s 45-minute grilling at the end of Tuesday’s session.

During the final months of Kalanick’s eight-year reign as CEO, Uber acknowledged rampant sexual harassment within its ranks, a yearlong cover-up of a major computer break-in and a $100,000 ransom paid to the hackers, and the use of duplicitous software to thwart government regulators.

Levandowski subsequently destroyed the disks, according to Uber, though a firm hired to analyze the risk of buying Otto didn’t find concrete evidence of that disposal.

Levandowski has declined to answer questions, citing his constitutional right against self-incrimination — one reason Uber fired him as the head of its self-driving car division last May.