Does anyone have photo of the route?
On a broad sort of climb like Weeping Wall or Gibraltar you can have 4 or so parties climbing all at once and no one below anyone. Is this a case where they could have picked the other side and they chose to climb under you,or a case where they had no choice?
As mentioned - high winds, weather changing - puts the desire in ppls heads to "get this thing in now while we can" and false sense of urgency leads to higher acceptance level for risk.