Ok, this still fom the ROV video is a bit further up slope of the reef shelf. It is a sheet of that 'alloy' material again similar to the curved/concave bit on the reef shelf. It has the same oddly 'serrated' edge to it again, with some symetrical positioning of holes? rivets? black lines, and is very thin. The yellow line goes around the outline of the 'alloy' sheet and, it appears to be 'square', 'panel' shaped?. The red lines go around unusual objects lying near or, on top of it.
One has a metal ring at the end of it, one looks like part of a set of goggles, two appear to be metallic parts and the rest, who knows. Again, like Marty says there have been a lot of visitors to the island over the years and, we don't know for sure if another plane ditched near the island, maybe during WW2?
So again. It's speculation but, there is something on this reef.