I'm going to venture a guess that the jacket was not found as we are viewing it in the picture. While I could be wrong, it appears to me that it was fished out of the water and placed there in order to get the picture, although I've seen no mention of that in MSM. Only that it was found "behind the apartment".
That jacket looks pretty wet, while the ground and leaves look dry (except the one on it), which is why I think it was fished out, dropped there, and had this pic taken. If that's the case I wonder why it hasn't simply been stated "a jacket was found in the water"? Not that it makes a whole lot of difference, it just doesn't appear factual to me the way it's been related to MSM. MOO
Pivoting... Does it seem likely that a jacket could come off a person from water that doesn't appear to have much movement? I can see where clothing may come off in the ocean with all the wave and tidal movement. Not to mention marine life nibbling at it. But in that still and not very deep looking water?