Think I’ve just hit a bug with Safari Version 10.0.2 (11602.3.12.0.1) on El Capitan.
With accessibility turned on, the media player breaks tabbing navigation. The media window is highlighted but the play/cc buttons can’t be activated and pressing tab again takes the user out of the page into the Safari bookmark bar.
Means that any components after the Media player can’t be accessed with keyboard.
I hit the issue in the Authoring Tool. But just replicated with a fresh install of the demo course using CLI.
I can’t play or navigate past the video with keyboard only.