One of the many times this was reposted, someone had an interesting explanation. These walls are pre-fabricated, and they were mixing up the sections that go on the right with those that go on the left, or maybe walls from other sides of the building.
I saw something like this happen in a new hospital building. What they were doing was cutting the original wood for the headboard, then they used that as a template for the next one, which was used as a template for the next one, at least fifty times. By the end none of the shit lined up at all and it all had to be redone.
I like to shit on Word as much as everybody else but the problem here is obviously that they didn't use a mono-spaced font when they made the blueprints for this building.