Really? If the video is not admissible evidence, then why was it shown to the officials?

The new rule limits the use of a video, but they do not prohibit it:

"New Decision 34-3/10 implements two standards for Rules committees to limit the use of video: 1) when video reveals evidence that could not reasonably be seen with the “naked eye,” and 2) when players use their “reasonable judgment” to determine a specific location when applying the Rules."

I think the the first exception would apply to this situation because the player could not see the ball when taking a practice swing. My opinion.