Mark, we measure Road Races.
I suggest you tell the race you have measured as described and done so according to our standards, but USATF doesn't issue a certificate for XC courses.
As you know there are too many variables on these type of courses. Next time the course is run, I would bet things will not be setup as you measured. However, at least the course will be reasonable accurate.
As a HS and College XC coach, I found too many courses over the years and run differently each year. Also,i found many courses not what distance they claimed.