When Dr. Peter Ward took him to that outcrop on shore I thought we were in for a fantastic show... a couple of hits with the rock hammer... they came real close to showing that ammonite up close... never did get a good look.
I saw the octo and squealed to Neal, "That's Biddle!". I watched closely and noted the white underside against the black and am still thinking the one shown (another shot WAS identified as the coconut octo but they did not say about this one. I tried to listen carefully and I don't think they said it was unidentified, they just did not say. The "new species" they showed shortly before had to be a Abdopus aculeatus) was an O. marginatus. It was found in the same region where Muctopus displays photos of hers and where the others are found that were in the tank at the store and believed to be Abdopus aculeatus.
From what I could find, if it was O. marginatus (I think Mucktopus said close but no banana) Biddle should have a very white underside even when she turns black. One possibly identifing feature of whatever she is is that she turns black and not white when frightened. My merc and all the videos I've seen show frightened octos turning white so I suspect this aspect might give a clue.