Congrats on your first deer and its great that you have it on video.
I' ve taken a couple of deer through the liver and its usually a 40 minute wait before they' re finished. They usually don' t travel far, maybe 50-75 yards but then they stand acting sick for a while, then lay down. Even liver and one lung, your deer seemed to expire very quickly. My bet is you caught an artery, the one probably that drops beneath the stomach.
What ever, I bet you and your dad were really pumped. It proabably was a high for him as well.
Happy Hunting
Dan