<StateSpecificName>_AllFields_Sample.xml does not contain a working incident and it follows the FBI's lead of using it only to show the syntax for all the elements. Please note that some tags may appear under an element where it doesn't make sense. For example, the FBI has taken the <Item> element and reused it from another namespace where it's defined for general usage. This means that the <nc:ItemQuantity> tag appears even for property loss types Counterfeited, None, Burned, etc. NIBRS is using it only to count the number of vehicles because motor vehicle theft is important to them.
Attached is the FBI's xml Developer's Guide that goes along with the FBI IEPD and that vendors may find helpful.