While not scientifically precise, the tape reportedly shows a puff of white smoke in the sky (in the path of FLT 587) after the plan hit the ground. An explosion in the presence of JetA as a fuel source produces a fire (flame front) with a distinctive orange flame and recognizable brownish-black smoke. This is a real tell-tale for anyone fighting a Class B fire. [think of the smoke cloud you saw from the crash fire on the ground, or sadly, the smoke from the WTC, especially initially at impact]
I do not see a puff of white smoke (could be steam, but not likely) as evidence of an explosion at the wing root. I do not pretend to know what it was, but I do not see it as an explosion.