I assume that BA got hit with some sort of supply issue and is now looking for a new supplier / waiting for the old supplier to lower prices to the old level. The definition of safety stock is that it is enough stock to keep them afloat with premium champagne until they find a suitable alternative or another supplier. So either BA kept no/too little safety stock or they don’t care about a 3 week service disruption with respect to the champagne. In my optimistic point of view I just assumed the former.