I've been involved in more than a handful of interviews where it was clear that the candidate was wearing an earpiece or getting answers from someone else. Never hired an actual impostor like in TFA, but the signs of someone cheating the interview were pretty clear.
All we had to do was go off script and we'd have a good idea about how genuine the candidate was being.
I did an interview like that once where I could actually hear the colleague whispering answers to the candidate, during awkward pauses between when I asked a question and the candidate responded. I asked him "are you getting help from somebody" and he straight up denied it.
It's one thing to have outright fraud, or people who want to screw over your company for a free paycheck.
Having someone early in their career, really nervous and wanting to succeed ... I can just see a college dorm buddy saying 'hey man, I'll get you the answers from Google!'.
It might have a kind of 'immature prank' element to it as opposed to 'nefarious intentions'.
If this happened to me with a kid just out of college, and they were visibly nervous, I'd actually ask them to take it out and have conversation with them about what that kind of behaviour implies, why it's wrong, that they are lacking in self awareness to think they are going to get away with it.
I also feel that some people grow up in cultures and family / community situations which are just completely toxic. They have no faith, belief or understanding of how people get along in normal, productive societies. They've never remotely been exposed to a professional environment.
In fact, professional behaviour is a hallmark of well organized civilizations and hiring people from any place that is not '1st world' you get these kinds of issue quite often. It happens everywhere obviously, just more often in places with zero exposure to certain kinds of social socialization.
Finally, I believe that these kinds of problems are going to be more common with remote work as one of those issues for which we have yet to contend with. Anyone who's worked with offshore teams understand the struggle, now we're going to have those issues with greater preponderance in remote orgs.
All we had to do was go off script and we'd have a good idea about how genuine the candidate was being.