OSX Contacts "remove duplicates" log of changes done?

I've seen plenty of tips on how to remove duplicate contacts using OSX's Contacts application.

I've done the process and I'd like to know if there is any record/log of what changes the app has done - I'd like to know what contact it has changed. I have almost 3000 contacts, and it claims it's changed/merged around 300, but looking for them manually is not really an option.

I've googled the question with a few variants but haven't found any answers. Looking at the Console app didn't show any clear log entries either...

Thanks!