My favorite CAD story came from around the time when the ability to create 3D renderings from the plans came around. The company my dad worked for had a disagreement on the location of a set of pipes running along a corridor. Once the 3D render was available, it was clear that the plans were very wrong and would have placed the pipes in an impossible manner. I never did learn why the CAD ops were so sure they were right, but just one of those funny stories that stuck you just made me think of it again.