(VIDEO) Decoding S-300 Missile Failure - Any Idea?

This is a popular video on the open web. Can anyone understand how exactly this exploded mid-air.

S-300 Surface-to-Air Missile Strange Failure

Between 0:29 to 0:33 seconds something opens up from the sky, like a blue light...

(VIDEO) Decoding S-300 Missile Failure - Any Idea?