Oh my gosh, that could have ended SO differently (and SO tragically!!), with the humans finding their dead cat (or a cat head or leg or something) the next morning.
This is also timely for me because my neighborhood email list just had a post asking "Whose cat is this?" It's not mine -- all of mine are indoor-only and will be forever -- but it's a beautiful kitty that I've seen around the neighborhood. The human owner finally emailed the list saying "It's mine" but nothing else ... no "Sorry, we'll keep him indoors from now on" or "Sorry, we just realized how dangerous it is for cats out there" or anything. Just "he's ours." Well, he might not be for long if you let him roam freely around the neighborhood.
I posted that I've seen lots of foxes lately (including in my back yard in the last few days -- there were 3-4 of them, including some very young ones), and I know foxes don't often attack cats, but they certainly COULD and HAVE. And I know I would be absolutely devastated if one of my kitties got outside and I lost him or her forever.
Anyway, OP, thanks for posting. That video was pretty amazing.