Sometimes a course measurer represents the last chance for a race to avoid disaster. Bad course design often means a horrible experience for the runners, and it's the runners we are doing this for, right?
Some of what I think I know about course design comes from my experience running races. But a lot of it comes from mistakes I have made, often when I have gone ahead and measured a badly designed course. Then I hear about the disastrous consequences.
The worst example I can remember happened when I was measuring a 10K course in Jakarta, Indonesia. The course I was presented with "crossed over itself" in that a later bit ran across an earlier bit. I had concluded that the distance along the course between the two parts was long enough that there would be no problem of traffic or confusion between slower and faster runners. So I measured the course as presented to me and came home.
My U.S. contact was livid. He explained that in addition to elite runners (who the promoters hoped would set a WR for 10K) there would be masses of regular folks joining in for the excitement, and so this "self-crossing" just would not work.
Long story short: I had to go back and measure a redesigned course-- i.e. fix the mistake I had made by just doing as I was told and not questioning enough.
I believe that someone actually did run a WR 10K time on the course. But I haven't been able to confirm that.