Anthony Levandowski's attorneys argue that the court overstepped constitutional boundaries by pressuring Uber to fire him if he refused to testify.

Uber has fired Google engineer Anthony Levandowski, the autonomous driving pioneer at the center of a lawsuit filed by Alphabet's Waymo.

The lawsuit accused Levandowski of stealing thousands of proprietary design files from Waymo and using trade secrets to develop a lidar sensor system for his new employer.

Levandowski asserted his Fifth Amendment rights to avoid testifying in Waymo's lawsuit against Uber. A judge recently hinted that Uber could face consequences for keeping him on its payroll without demanding testimony, however.

The engineer's attorneys argued that the court had overstepped constitutional boundaries by pressuring Uber to fire him for his refusal to testify, but the company nonetheless followed the judge's advice and terminated his employment.

"Over the last few months Uber has provided significant evidence to the court to demonstrate that our self-driving technology has been built independently," Uber's associate general counsel for employment and litigation, Angela Padilla, wrote in an email to employees, as quoted by The New York Times. "Over that same period, Uber has urged Anthony to fully cooperate in helping the court get to the facts and ultimately helping to prove our case."

A termination letter obtained by The Washington Post also accuses Levandowski of impeding Uber's internal investigation and failing to comply with a contractual commitment to destroy "all property and confidential information belonging to any prior employer."

Notably, Levandowski was not listed as a defendant in the lawsuit and Waymo must still prove its claims against Uber as the legal battle moves forward.