I suspect there may be something more to this than incompetent officials. Maybe it was intended that the gate should be open for the event, but permission was withdrawn late, and the map didn't get updated/overprinted to show the gate as impassable? Perhaps planner and controller got so familiar with the forest that they knew the route was impracticable with looking at the map, and didn't notice that the map showed it as passable? (- an easy oversight, I've made similar mistakes myself when planning).
As for me, I didn't read the map carefully enough to realise that the 'road' (over the viaduct) was level, avoiding the down and up, and so took the long but level track route through the forest. The right route choice as it turned out, but made for the wrong reason.
