So, what is the issue? It is common for people to not be hired into sensitive positions because they are not citizens. When I used to hire people, I *only* hired US citizens. I'm pretty sure that even our interns had to be citizens. This was in a DoD facility.
I'm certain that Elon Musk has a lot of sensitive projects going on, considering that his SpaceX company works closely with the government. Most likely his company cannot legally hire non-citizens. This lawsuit will be thrown out.
Exactly my thinking, especially if the position in question was in a sensitive federal project. The contract might even have a restriction on what citizen status the personnel had to have.
I would think that if the applicant had the correct visa to work in the US, they would have stated such in the article.