[themaninthedark]

Right but the purpose of the trip was to attend the business meeting and the person on the trip was also conducting their regular duties as a developer as well.

Attending meetings and conferences are rarely the main duties of an employee but they are the main purpose of trips.

Similarly to how, if you go to Mexico on a Tourist Visa but answer a critical work phone call you would not be breaching the terms of your visa as the purpose of your trip is still vacation. However if you rent a house for 5 months and spend most of that time doing developer work, I think that the authorities there might be a little upset.

[orwin]

From what I've read it's still an ESTA violation. When I went to the CES a few years ago my goal was clearly work, not vacation, and I did work from my hotel. I should have been arrested and put in chains, then publicly shamed for that I guess, even though my employer asked me to.

Was only planning a single family trip in the US in the next few years anyway, and Trump nicely gave me an argument to visit the Carribbean instead (because yes, I intend to work a few days from my vacation,I have to when I take more than a month off).

[themaninthedark]

Can you provide a link to where you read that? I can't find anything that states that, nor can I find any news where that has happened.