In a true situation, we do not remove SHI listings. Stolen or missing always stay up in genuine cases.
CL removes postings if the person posting posts too much or someone else says that they are the rightful owner. This is where it could be sticky and civil. The need for a listing with SHI to find the horse and determine the rightful owner... if this is a civil situation.
Just have to find out what transpired for the horse to disappear or be stolen. But, they have to file first.