I guess we can take away that real money is part of the buying today as the market ran EUR/USD up to a new session high at 1.3901 at the 16:00 GMT fixing. Money managers are the heaviest users of the fixings and the 16:00 fixing is the most watched one of the day.
Could be that managers had hedged for a lower EUR and are caught out just like everyone else. Purely a guess on my part.