So they hired a professional interviewee to be interviewed for them? Amazing. I wonder how you'd get that job, and what the recruitment process would be like?
This is not uncommon in IT type jobs with individuals from a certain country. I was at lunch with a coworker when he was approached to do an interview for a cousin of one of his friends. I must have looked puzzled because he explained it to me and I was flabbergasted. He said that it was more common during phone interviews, but since "they all look the same" to white hiring managers, it still happens over video interviews.
It's more they have a friend that speaks better English do the interview and hope that big companies don't notice a difference when they start the job.
Had that happen to me once. Guy we phone screened did not match the guy on the video interview. Immediately bounced, you could tell their accent and talking style was different.