In the WOC sprint final, a large old gate to a park that is usually permanently locked is just shown as (part of) an uncrossable fence. On the day of the race, unknown to the organisers, it is suddenly opened before any runner has reached that point. It is passed on one of the two obvious routes and 30% of the runners go through it since the control is just near it and this saves 200m of extra running.
The map was effectively incorrect so the runners who went through the gate cannot
reasonably be disqualified.
This is interesting, because gates that might be open or closed during an event (and therefore can't be allowed as a route) occur quite often in urban events, most recently at Cambridge. The IOF document suggests that mapping them as uncrossable fences is "effectively incorrect", which raises the question, how should they be mapped?