Yes, he got legal advice on setup & ensuring the business relationship with the Foreign company (in the Netherlands) in terms of the  contracting with the company.  He set up the US company as an LLC in 2019. 

To  complicate even more, he also received income from England. On this income, no taxes were withheld. 

I'm going to speak  to him to get more details on the business relationship and the legal guidance he received.

He got his GreenCard in 2019.