Insurance companies send a claims adjuster to inspect it themselves. They aren’t just going to fix your car unless they think it’s covered because of some type of accident. It sounds like they agreed with Tesla at their expense.
Have a read about how it works: https://www.morganclark.co.uk/loss-adjusters-your-questions-...
12K claim on a car that was allegedy sold as new 24 hours ago? Super unlikely a loss adjuster wasn't sent and came to the same conclusion as Tesla.