Ive got a similar question, and I feel I’m very close to a solution. Hopefully someone can help tip the bucket on this:
<a href="https://maccessibility.wpengine.com/wp-content/uploads/2015/09/Upscale-2015-Draft-02.mp4" rel="wp-video-lightbox"><span class="button hvr-sweep-to-right">Watch The Video <i class="fa fa-angle-right"></i></span></a>
The issue is: a lightbox fades in and the loading icon works for a moment, but eventually errors out with, “The image cannot be loaded.”
Other than that, If i remove the rel="wp-video-lightbox
the video opens like a link and plays beautifully.