How to prevent screen reader users from clicking directly on video & de-syncing from timeline?

Thank you AaronBurgessAU​ , this solved it! By setting Video Tools / Options / Play Video: Automatic and then creating a trigger that basically causes a useless action when the user clicks the video (i.e. Set state of Dummy Rectangle to Normal when the user clicks Video) this prevents direct play/pause of the video when selecting the video with the keyboard. (Demonstrated in slide 1 of the attached .story file)

Interestingly (this might be a bug in Storyline) but clicking on the video with the mouse in the above configuration still pauses/plays the video, causing it to de-sync with the timeline. To workaround this, I created a 100% transparent blocker rectangle that prevents mouse clicking on the video. This, along with Aaron's solution above, seems to be a holistic solution (Demonstrated in slide 2 of the attached .story file as the Final Solution).