Don't know any more than what's posted here but this sort of thing - aircraft trying to land on WIP short of a temporary displaced threshold - has happened many times and the world over. Whatever the reasons, clearly it is all too easy to do.
In these days of safety management, maybe it's time to close runways when there is work going on.....not that that is any cast iron guarantee that no-one will try to take-off or land on it, I know, but at least it reduces some of the risk.