Thanks for that scenario. Those potential ramifications are significant. In that specific case, one could imagine ponying up for a steep same day ticket from Thailand to keep up the ruse. One would expect there would be innumerable psychological tolls to live this way.

What about a subtler case? You begin working as a US based employee, but after enjoying your work and proving your mettle, you take the risky choice to move abroad without informing your company? Or, you have a US based apartment but periodically for a month here and there operate abroad unannounced?

Additional wrinkle: while the expectation is more clear informally, it's not clear to me what US based employment is from a legal standpoint. Is it merely filing your taxes from a US based address?