Also, I got another reply which also seems possible.
When I do graphic art design for someone, I send them everything in PDF form so any text, graphic or background color can be modified easily. My guess is that the artist sent the file to be approved and the receiving party, not knowing anything about layers, approved it and ran with it.
What is known about the obama staffer who died last week...the 29 year old fellow....what was his expertise in layering, graphics, etc?