Unwanted border appearing on video element

In the video you linked to, the border line along the top of the video is part of the video file itself, so it's an issue with the original file or the way you edited it. (I often have this problem with videos. Quite annoying.)

A quick visual fix with CSS would be to pull the top of the video up a bit and hide the line at the top:

.video-js .vjs-tech {
    top: -2px;
}

.video-js {
    overflow: hidden;
}

But yeah, that's a little cheeky.