Good video, Henry is definitely the same species as Octane.
How bid was the starfish? Because chocolate chips have a reputation of killing and eating fish (as do green serpents but I have learned there are two kinds and Mr. Green Jeans looses his arms regularly but doen't hurt anything) I have avoided them so I have no direct experience but if it attacked the Octopus, it may have been killed in self defense or killed as an expected preditor that was too small to do damage at its current size. You mention it was not eaten, was any part dismembered?
the star fish was about 2.5 inches across. one of his points was broken in half and hardly hanging on. i had noticed he had a few bite marks a couple days ago. i think henry just decided to finish him off. lol