Posted By:
petecldTher's one in every bunch. 
The printer (pressmen) doesn't choose the colors. That's not his job. Proofs are approved for (final)color BEFORE going into mass production. The pressmen would never make the decision to take the brown plate and use blue ink unless he hates his job. That makes no sense.
The extra printing done on the right image is from a different card and they had unfinished sheets sitting around and used item to adjustmnets for the next card. Quite a common thing for a pressman to use, using fresh stock would be a waste.
You even killed your proof claim even farther by noting the over printing is the next card in the alphabetical line. What would you most likely have sitting around when you are preparing to set up card #10 - scrap sheets from card #9 - right?
BTY - When I say the pressmen "adjusts" the color on press that doesn't refer to the ink color itself, just the registration and ink thickness. The ink color is dertermined long before the pressman gets the plate(s).