Ghost Caught On Video Shattering Glass Cabinet Door, Barnsley Antique Centre, South Yorkshire

 Couldn't see any type of projectile fired at the glass door then again video
 Quality not good....small pellet maybe or ball bearing from a sling.....
 Then again the glass shatters outwards with a lot of force... not sure on this one...

Toughened glass is weird.  I've had double glazed units explode when brought in from the cold at work.  You could put a unit across a couple of bearers and stand on it, but a tiny tap on the corner can make it go bang. 

On the floor are a toolbox and what looks like the contents of the cabinet.  Maybe someone was replacing the door and had overtightened a hinge, which could stress the glass as it warmed up in the room.