John Woodman speculates that some special software could make layers and
"some optimization process" (that John does not specify), but Obama's claim is
that the PDF is a simple scan of a paper document. We need to see the paper.
John did not show any experiment, scanning a document, to show that it produces layers. He speculates on "some software" that would. As a professional he should have a scanner and such software in his office.
John speculates: the signs of forgery are so bad, that no forger would be so stupid. Therefore the document was not forged. But he fails to consider that the forger knew layers would be a clue, did not like what Obama was doing, and deliberately left clues. For example, the smiley face on the A of Alvin T. Onaka PhD.?