You had the clean run/walk that eluded me (and some others). Nice work!
I found it interesting that your estimate for a perfect run was so accurate...I was not going for that time, until just after leaving 8 I noticed my time at 39 minutes, which gave me incentive to be careful for the rest of the course. Still, 80 minutes for 5K seems awfully slow.
It's weird. My naviagational speed (speed without mistakes) is about 12 min per k for most northeast venues, but for Harris Center it's about 17 min per k, 40% higher. The only venue in the northeast even close to that is Burnt Mtn.