Well, I made a picture of what the old bad scale (red lines) and correct scale (black lines) parts looked like:
As you can see, the first 2 sheets aren't too bad, which would make it pretty hard to notice the error. The last sheet is quite a bit too large though.
I have no clue how they ended up with these particular scales. My original theory is that they were scaled to fit the available output, but none of the dimensions match the expected paper size, and the last one is bigger than the nominal paper, so that pretty much kills that theory.
As you can see, the first 2 sheets aren't too bad, which would make it pretty hard to notice the error. The last sheet is quite a bit too large though.
I have no clue how they ended up with these particular scales. My original theory is that they were scaled to fit the available output, but none of the dimensions match the expected paper size, and the last one is bigger than the nominal paper, so that pretty much kills that theory.