Mary “Missy” Cummings, an engineering professor at George Mason University, told jurors in Miami federal court that the Tesla owner’s manual, which contains critical warnings about how the system

A critical voice took the stand Wednesday in the first-ever federal jury trial involving Tesla’s Autopilot system: a safety expert who says the technology is defective and promoted in ways that encourage misuse.

The complaint alleges that Tesla acted recklessly by allowing Autopilot to function on roads it is not designed for.