In my state there is a law that makes false call to 911 a criminal offense. If someone says “there is a bomb” on such call, that makes it more serious offence because this will cause public alarm. If the person making such call is stupid enough to do it from their phone, they will likely be identified and prosecuted. And people doing stupid things tend to be that stupid.

I’m not sure about damages caused by the raid, though. SWAT doesn’t know if the threat is real or not, so they can’t be held liable. Probably the victim can sue the caller, if they’ve been found…