The purpose of this site is to show how the groups in Adobe Illustrator can be revealed. This does not necessarily mean the document is not real. There could be many reasonable explanations for why the grouping gets revealed in Illustrator. Many people think that this apparent internal grouping in the document means that it was assembled rather than scanned. If this is true, the document could be declared fake.
After additional research, it appears some scanning software will attempt to isolate words within the image to facilitate optical character recognition. It appears very likely that is what is going on here.
Up to now I've been convinced that Adobe Illustrator MUST be deriving or somehow figuring out these layer groups at time of opening the file. For the layer group data to be present in the actual file would imply the program that created the file "knew" of these grouping at the time it created the file. If this was the case, then that saving program would have had to created the grouping (I don't know of software that does this, but is possible), or the grouping is a common "layer" feature used in PhotoShop.Step 5: View Any Layer Groups
This is where it gets interesting. Adobe Illustrator shows NO layer groups at all. It just sees this as one big image. This tells me that the layer group information was additional meta data inside the PDF file that was released. That meta data containing the group information had to come from some software that touched the file between scanning and saving as a PDF. The big question now is whether that it came automatically from some smart logic during scanning or was a result of image manipulation in an editor like PhotoShop. I'll leave the door open to both possibilities, but the former seems like quite a long shot.