I recently changed my username on drupal.org, and as a result is now different from my git username.
When you attribute a patch someone else using the commit author, you use the anonymous email address, which is based off of the git username (which also shows up in that user's profile page.
When you can commit directly to a project, there is a standard format for commit messages:
Issue #[issue number] by [comma-separated usernames]: [Short summary of the change].
Are these supposed to be the git username or the drupal.org username?