Perhaps the friend needs to do some of their own research and/or ask their own questions. since there is so much strange or missing information in this post.

Thinking the airport is a Federal property and that there is a quarantine upon entry makes it sound like either the OP or the 'friend' is not from the US.

Where does the company think they will hold the interview? (I can imagine that perhaps both interviewer and interviewee will be flying in and possibly use one of the lounges at the airport).

Does the "friend" have the necessary passport or other documents or permissions for access to the meeting location?

My friend will be flying in from South Carolina, interviewer is local to San Francisco. Interview can take place anywhere in the airport. Sorry if you found more info needed. Hope this clarifies. He is not trying to dodge any legal issues but is trying to stay within the Governor's orders but still do the interview.

AND they will have to stay 6 feet apart? I hope this is at least a second or third "interview", others having been done via zoom of skype. Sort of the final decision

There is no required quarantine entering either SC or California.

They will both need to wear masks and social distance. Seems hard to interview when mask wearing and social distancing. I'm not even sure where, outdoors, they could meet unless the friend Ubers to an outdoor meeting place. There seems no advantage to meeting "inside the airport" so I'm wondering where this is coming from especially given the strict Shelter in Place orders in California.

Unless this is some kind of emergency or urgent employment need such as health care, the whole thing sounds a little fishy. Hope it is not a scam.

Is the potential employer paying the air fare? Usually they do if they require a face-to-face interview which requires travel. If they're not paying, I would seriously question the whole thing. It just seems a little odd.

Honestly, at least half of the young people I know are in the tech industry, my son included. He's been doing quite a bit of hiring lately, and no way would he require the candidate to meet him in person at this point in time. He and his employees have all been working out of their homes since mid-March.

My neighbor had at least 5 interviews for a tech position in April. Not one interview was in person.

Yes, my friend has done several Zoom interviews, 2 with this company. That's the odd part here. The potential employer will pay all expenses, airfare in advance. As you can imagine, good jobs are fairly scarce right now, so he's trying to come up with a way to expedite the process and show some initiative. The "in person" seems to be a company policy, likely not revised since so few employers are hiring lately. This would be his 3rd interview.