I suggest using the "GeoLevel" field to make this decision. Depending on your application, you might only use coordinates for matches made at the "Street" level. Here are the possible assignments from the documentation:
In order of ideal match:
Street:Address is assigned to its interpolated street location.
Intersection:Address is assigned to the intersection of multiple streets.
Extrapolate:When an input address is out of range, the Geocoder assigns the address to the closest known valid street segment.
Example: Main street has valid addresses in the range 1-100. The input address is 127 main street. Its not a valid address, but it would get assigned somewhere near 100 main street and the resulting GeoLevel==Extrapolate.
Zip 5:Address is assigned to the ZIP Code centroid.
Note: When Geocoding a PO Box, a ZIP 5 centroid is the best match possible. The ZIP code that gets matched is, in most cases, the point location of the Post Office building.
