"I realize I made mistakes in the development of that part," Raymond DeGiorgio said during a videotaped deposition played at the first trial in federal litigation over the switch.

DeGiorgio worked for GM for 23 years and was responsible for the switch's design. He was terminated in June 2014, months after GM began recalling 2.6 million vehicles because the switch could slip out of position, stalling engines and cutting power to vehicle systems. It has been linked to nearly 400 injuries and deaths.

DeGiorgio said he realized in 2002 the switch did not meet GM's torque specifications, but approved it because he did not think it could endanger drivers.

DeGiorgio signed off in 2006 on a redesigned switch without changing the part’s number, which later confused investigators probing crashes. The engineer who discovered the discrepancy, Mark Hood, testified Thursday that it was “very unusual” to change a part but not its number.

DeGiorgio has previously told investigators he does not recall the circumstances surrounding the part change. When asked whether he thought he was a scapegoat, DeGiorgio said he had at first, and that his firing had been a “shock.” But after “recognizing that mistakes were made along the way, I don’t feel that way anymore,” he said.

DeGiorgio, like many current and former GM employees linked to the switch, will only appear at the trial in prerecorded depositions.

Lawyers for Robert Scheuer have been trying to convince a Manhattan jury that GM concealed the defect for years and failed to conduct a proper recall. They contend the switch in Scheuer’s 2003 Saturn Ion rotated off, preventing his air bags from deploying when his car crashed in May 2014, just weeks after he received a recall notice.

GM has disputed that the switch failed, or that Scheuer’s air bags should have deployed under the circumstances. The company previously acknowledged that some employees knew about the switch problem for years before the recall and has paid roughly $2 billion in penalties and settlements over the part. The automaker still faces several hundred lawsuits over injuries and deaths, as well as lost resale value.

(Reporting by Jessica Dye; Editing by Alexia Garamfalvi and David Gregorio)

By Jessica Dye