I'm an Easy boot distributer and I get a newsletter monthly. This article was in the newsletter I got today...a report on the stats from this years Tevis. I thought it might be of interest since we had a discussion a while ago about how many endurance horses wear boots versus shoes.
My guess that the boots they used were the glue on "glove" shells versus the typical pull on and off boot. The glue ons stay on for a few days when glued on properly and are not meant to stay on full time.