Google Maps terms of use make no distinction between use in the "strict sense" and regular "use", nor does it indicate that using it as a "supplemental source" is ok.  It doesn't matter if "not a single edit would be different" if you had not used Google Maps, the fact is, you used it, and that is a violation of the terms of use.  There was nothing wrong with the wording in your changeset source.  You were honest and admitted that you used Google Maps.  As a new user you can be forgiven for using Google Maps, but reinstating the edits once you have been made aware of the facts is a different matter.