That's pretty amazing. Make me wonder two things:
1. Why hasn't anyone tried this before? Seems pretty easy...
2. Statistically, what are the odds of running into a giant squid like this in the few hours that they had that thing released? Either they got very lucky or there are a lot more of those giant squids than people realize.
Look at the way it sways its tentacles. If I was to estimate intuitively, I would say it was in the 10-20 foot length, but not the incredible estimates that guy is making. I don't think those depth of field calculations are even possible with a 2-d image!
The narrator says they're using "light throw and depth of field data". If we assume there's some kind of light attached to the camera, they could certainly use that to approximate distance. Or if not that, the focal length of the lens coupled with how blurry it is could give a very rough idea. So I grudgingly admit that it's possible, although I would prefer to think they're all getting excited about a 2' long squid that's just a couple of feet away.