Corks gone wild.

No, there aren't any angry corks marauding around Vinoland - just an over zealous human-corker perhaps.  Accidents happen.  Besides, this particular bottle might simply have had a weak spot on it's neck or shoulder.  Such a flaw in the glass would cause the bottle to break when pressure was applied from the hand-corker.  But rest assured, no wine-drinkers, or Vinodogs, were hurt during the bottling of the 2011, St. Helena Cabernet Sauvignon (clone 7).
A leisurely lunch followed; corks were pulled from miscellaneous bottles and after a while the broken bottle was forgotten. 
Job's a good 'un.