OK, here's a theory... seeing as how high it got...
If the kid was in there, and unhooked it... I'd imagine the balloon rose pretty damn fast, and the way that it was spinning... I imagine the child fell out, if he was in it, moments after take off, probably falling out a few blocks from the house.
The way that think was flying: speed, rotation... it's possible it could have closed the door, if it was opened.
Weird, weird story... a thanks to the OP...
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