Not at the moment but the scanning feature is client-side only and does not rely on any external services. It uses jsQR[0] to handle parsing directly in the browser. One way to use it and be sure would be to load the page and disable the site's network connection using developer tools before giving camera access. Once done, allow camera permission, perform the scan then kill the page.
[0] https://github.com/cozmo/jsQR