I agree with Phil on this one -- it could be a gigantea.
I think there's isn't enough information to definitively ID this anemone. There is quite a bit of speculation, but without a look at the underside, it's hard to tell what kind of anemone it is.
For the same reasons a few have thought that this might be a transplanted haddoni, I believe it could also be a recently transplanted gigantea. I stress "recently" because on our home aquariums, all acclimating gigs look similar to the anemone in the video -- short tentacles that resemble haddoni. Maybe it was moved to its location because it was easier to film. Maybe it was moved so that tourists could view it. Maybe it's something as simple as an environmental condition -- that the tide recently came in and the anemone, which was exposed to air, was still in the process of inflating.