My personal experience with the many copies I’ve made over the years is that scanners tend to stretch the drawings a bit. The top starts out pretty close and by the end it can be off quite a bit depending on how big the plan is. You then have it printed on paper that is less than optimum for plans and so you will have a lot of shrinkage and expansion depending on the environment. It can very quite a bit with the various printers, but that is probably what happened. Printing directly from a CAD drawing is obviously considerably more accurate, the problem comes from the scanning and the various scanners in my opinion.
Luke