I’ve not encountered that I’m afraid. I’ve seen people post images of scratched screens and genuinely not know how it’s happened. My wife’s friend scratched the screen on her iPhone 11 but had no idea how it had happened. Obviously it had been scratched by something in a pocket or on a surface, but there is acceptable wear and tear. I’ve not seen anybody claim a screen has scratched from thin air.
Unknown scratches are one thing we've all experienced, but more common is outright lies.
When I worked at the Genius Bar many years ago it was funny how some people had no idea how they got Diet Coke inside their phones.
Or "I swear I just pulled it out of my purse and it was cracked like this!"
I was much more willing to replace at no charge when someone was brutally honest. One time a guy came in with his phone in pieces, with blood on it inside a ziplock bag. He said he got really angry and threw it out the window from the second floor of his house. Another lady had an autistic child who tossed her iPad and shattered it. Or a college kid who said she dropped her phone in beer while drunk. I replaced these devices at no charge due to the brutal honesty, since it was so rare...