I would like to ask about a theorical question that could have happened with a friend called Bob.
Suppose that Bob worked with Alice, both from a poor country P and their company had a contract with a customer located in a rich country R that had visa rules similar to the Schengen area where you can stay for 90 days for tourism without a visa.
So, the customer asked for a resource and Alice was alocated to this project. Alice went trough the visa process and, after 3 months, she got the work visa and went to country R. She did a good job there, the customer was happy, but after some months she decided to quit and to move to another company for a better salary/position and gave a 2 weeks notice. The customer was furious because the project deadline was near and they would lose a lot of money if it wasn't completed in time. Fearing suffering penalties, Bob's manager sent him immediately to country R without a work visa and asked him to say in the immigration that he would be 90 days receiving training. So, Bob went there, but was trained only for 1 week, working full time for the rest of the 90 days period, producing new features and generating value, under the "tourist non-visa" rule and not a proper "work visa".
Now Bob is back to his country P and wants to work legally to another company in country R, but is afraid to put in his CV that work experience since a background check could find that he never got a work visa and accepted to work in incorrect conditions.
Question: should he add or not in his CV that he had 3 months of work experience in country R? Considering that the experience/skills that he had there are really important and valued for the company that he wants to impress.
Also, how bad is to tell the truth to a new company that he accepted to work without a proper visa to help his former company?