Well one of the core issues is that if the photographers are taking it to the level of directly modifying images and inserting things that were never there, they're making it about themselves rather than about the subjects.
On another note if one looks at the bird's reaction when the other bird moves in you'll see that the bird with the frog has recoiled. In no case is the bird with the frog open to the other bird except when it's distant.
No it's not documentary photojournalism but it is nature photojournalism isn't it? Like I said if the photographs are ever used later for research purposes, etc. - they would be intentionally misleading.
This is why even something as simple as a bird photograph should be accurate. I commend the Bee for sticking to the time-tested principles of photojournalism regardless of the subject matter. It's called integrity and these days it's rare.
Stop worrying about grain, resolution, sharpness, and everything else that doesn't have a damn thing to do with substance.