Just grabbing the first fantastical quote from the synopsis: "He survives and begins talking about being able to look down and see the doctor operating and his dad praying in the waiting room."
Outerbody experiences are really intersting, I only just learned about this recently. The way we see the world isn't a perfect representation as viewed by our eyes, but rather a image put together by our brain (admitedly almost entirely from what we see). Our eyes are actually very poor quality, only the very smallest part at the center has a 'high resolution', everything else is really blurry, but the way our brain puts the image together we don't really notice this. Also it hides from us bits where the image isn't complete... like the Blindspot.. it's really quite a large chunk (from the hole that the nerves pass through) of our vision but we don't notice it because our brain fills it in (like a really clever photoshop effect). Also Our brain has a really intereting sense of what our bodies look like and where we fit into the world around us. If this part of the brain is damanged (like by a stroke) then our image of ourself in the world comes out of sync... people who experience this have a feeling that there is someone else near them, and it's like they're always being followed. Which sounds horendous.
Now outerbody experiences are when the brain shifts the viewpoint, it lets you see it's constructed view of your surroundings, and if you turn back your brains version of what you look like. It's not a perfect representation of the world or you, but because your brain is in full control of what you're seeing it never feels like it's not real. It's supposed to be very convincing. There is a perfect test to prove that you're not actually leaving your body though... put a random playing card on top of a wardrobe or somewhere in the room and in an outerbody experience try to see what it is. It's completely impossible. Neurologists understanding of outerbody experiences is so complete that they can actually be induced with drugs or with electric currents. I though that was amazing, I had no idea they were so well understood.
Key point is our brain has amazing control over how we see the world around us, it's very well understood. If a kid was having surgery and was near death (i.e. his brain started shutting down) it's entirely reasonable that his brain would start showing him some crazy s***, going in and out of conciousness he would definitely be having dreams. This sort of stuff is so well understood just by the normal funcions of the brain, there is absolutely no reason to propose supernatural explanations.