My advice is never give a live demonstration if you can possibly help it and never, never, never claim a property that the product doesn’t actually possess. Advice that Sonim would have done well to have heeded before handing over their “unbreakable” mobile phone to a reporter from the BBC.
The reporter, Dan Simmons, looked pretty embarrassed about having smashed the screen of the device and Somin’s CEO laughed about it and everyone is blogging about it but “unbreakable” it obviously isn’t.
You can see the video of destruction here.