"It exploded because of the pressure," he told reporters in the town of Pangkalan Bun on Borneo island, the search headquarters. "The cabin was pressurised and before the pressure of the cabin could be adjusted, it went down - boom. That explosion was heard in the area."
I am puzzled by this explanation and can only assume that the description given may have suffered some misunderstanding in translation. My guess is that the official is alluding to the sound of the aircraft impacting the ocean, and the pressure being that of the hydraulic surge that would have occurred on impact when water ingress through the ruptured underside of fuselage skin would have scoured through the interior, lifting the floor and bursting through fracture points developed at initial impact .
Some of the physics involved with water impacts was covered in post #3719 from the discussion of AF447 back in 2011.
http://www.pprune.org/tech-log/39510...ml#post6402729
The Hudson river landing (1549) is a good exemplar of the damage that hydraulic forces will induce even in seemingly benign situations (flat calm and smooth landing).
https://avtales.files.wordpress.com/...b-photos-2.pdf