A number of tests against the manifest file fire in schematron, but never generate output in the web frontend. Specifically, all tests where the schematron code uses as opposed to .
To reproduce, run the following file through the validator and observe there are no failures:
failing_manifest.txt

You should see an error "The value of Role (role) shall be main, alternate, commentary." (line 21) and "The value of the mimeType attribute shall be set to 'audio/mp4' or 'video/mp4'." (line 26). Both are tested with reports.