You’re thinking this is Yamamoto, who said he was holding Fuddy’s hand? He’s upright at the same angle the whole time so if he leaned back for his shoe to show he did it without affecting the upper half of his body. And there are a lot of extra bumps on the black part that don’t make sense even for a pair of pants. But from the image of the rescue it appears he was wearing dark shorts, not pants.
Look at frame 19. Where is the diver? The yellow is still visible, nut there is no ‘attached diver’. Sorry, the yellow is the sole of a shoe, what is being called the back of the head of the diver is the right knee of who ever is wearing that shoe with yellow looking rim on the sole.
I think it is Fuddy laying out in the water, with her feet at the surface, well her left foot anyway. Yama is the upright person, it looks like, holding Fuddy’s right hand. Her left hand is perhaps holding the tab (reddish?) of the inflatable vest. When Fuddy straightens her right leg, the ‘head of the diver’ is no longer in proximity tot he yellow shoe sole.