Chinese Guy Hurt Hand

[displayfireworks1]

I watched this video a few times. I am trying to figure out how the explosion by his hand occurred. Was one of the cakes upside down when it went off?

http://www.youtube.com/watch?v=zmx2fCfpI7o

[Pyro Nation]

That definitely looks like a cake was upside down or blew out the bottom. Which I may lean more to blowing out the bottom.