Match a user's contacts to subject ID's of other Oauth'd users

Question

When you use Google Oauth (or most other Oauth libraries), you get a sub (subject ID) to uniquely identify this auth'd user. Assuming the right permissions, you can then get this user's Google contacts. Assuming some of the contacts have also Google OAuth'd with your app, is there a way to match a user's contacts with the subject IDs of the app's other Oauth'd users?

I hoping of a more a definitive way than trying to match names, email addresses, phone numbers, etc, that my or may not be stored in someone's contact information in a canonical way.