Anyone using jQuery 1.9 or higher would be affected.
The recommended approach of using the on() method is not compatible with core Drupal jQuery, so we would be solving one problem while creating another one. I also looked into bind() but it turns out that's more trouble than its worth because of commerce_checkout.js which, to prevent double-clicking the submit button, clones the button when it's clicked. Binding this module's event handler to that new button is problematic.
I tested this using core Drupal (jQuery v.1.4.4) and jQuery v.1.10 (by way of jQuery Update module). Tested on both checkout and checkout review pages.