No conclusion, just a suspicion. And I'm holding on to it, no elaboration.
A while back I was on my way to Malaysia after spending a night in Hat Yai. I later learned that a bomb went off near where I had been staying shortly after I left the hotel. Which of course has nothing to do with anything, but it did feel close to home.
On the other hand I was once talking with a Chinese Thai who told me he used to have a fireworks factory in Bkk's Chinatown, he told me he got out of the business because of the ever-growing number of restrictions. This incident could have been just another of those disasters waiting to happen, like that blast in Lebanon a few years back.