With no speed work I think that's a decent effort.
Agreed, well done.
Also people really shouldn't put that much faith in their GPS watches. Try instead to measure the route using an aerial photograph http://www.usatf.org/routes/map/
Agreed, gps watches are dubious over that sort of range. They’re just not accurate enough, which is fine. Especially on a course with bends etc like this.
The point that had me questioning the distance only slightly, was the winning time by a very good runner - but that is completely unsubstantiated.
Aerial map would be tricky for this route as there is a 180-degree turn basically halfway down the middle of a road, so would be hard to pinpoint this, similar issue with start and finish.
And best of luck Dooby and Colm this weekend!