That's extremely strange.
I'm not a "forensic pathologist" as such but I have done forensic pathology to the point of appearing in court as an expert witness in that context. Before I semi-retired I was dealing with dead bodies every other day. I'm instinctively familiar with the way a position which was natural while rigor is setting in becomes grossly incongruous when the body is moved so that the structures that supported it in that position are no longer supporting it.
It's actually common sense when you start to think about it. Imagine any possible ways these bodies seen at 48 seconds into
Paradise Lost could have been lying on the ground or in a stream or in a storm drain or anywhere you like, to become fixed in these positions. I can't. And it's both of them.
Imagine them sitting on chairs, possibly tied to the chairs, and yes, it starts to make sense. See here.
https://i.imgur.com/Z2xvEjH.jpg (Still from
Casino Royale.)
The third body seen at 51 seconds is less obvious because the knees are together, but the same thing applies. It's not a natural position of someone lying on the ground when rigor set in. The arms and legs don't relax into the available space in a natural way.
I'm going to take a lot of convincing that these poor children weren't tortured while tied to chairs, killed in that position, and left there for a few hours while rigor set in before being dumped in the stream.