I've seen a couple of these jokers in the expat world in years past. A former copilot colleague faked a P1 license from the Middle East to get hired as a captain at Korean years ago. He flew left seat on KE A306's and B744's until his contract was no longer renewed.
A Kiwi acquaintance got in touch with me a couple of decades ago to ask about a possible bogus type rating on an FAA license used to obtain an ATPL for an African airline. I found a phone number for him to call, it turns out that the FAA ATP was real but the type rating was indeed phony.
These days you can easily check an FAA license online:
https://amsrvs.registry.faa.gov/airmeninquiry/main.aspx
Thomas Salme became a celebrity after he got caught flying for 13 years without a valid license, just another paperwork issue I suppose:
https://www.dailymail.co.uk/news/art...-13-years.html