If you've ever traveled abroad and replied to a work email or worked on anything at your hotel there's a chance you violated visa rules in some form. Very easy to find a violation if you want to find one, following the letter and not the spirit of the law.
It was an ESTA, and yes, technically working from the US with an ESTA isn't allowed. I'm not invited to the CES since I've left the first company I worked for in 2020, but I definitely would have cancelled all my plans to do so until this is clarified. If I needed a full visa to get there, I probably wouldn't have.
Also that's not what happened. The ones responsible for the breach, IE Hyundai execs and management who took care of the visa waivers and asked their employees to setup production lines were not arrested, only the people who had little to say about capital allocation were. In a way, Hyundai investors would have been a better target than their workers since they choose the execs who chose to build in the USA.
