The Dragon's Breath has been stated by its original growers to be an unexpected plant grown from Infinity Pepper seed stock that had been purchased from the Infinity Pepper's original grower and forgotten about.
I am currently working on reviewing the first commercial Dragon's Breath sauce and strongly doubt anything similar could be made with anything as mild as a Ghost or InfiNaga. I have no first hand experience with the Infinity itself yet but it's officially rated somewhere between the two, leading me to doubt that it and the Dragon's Breath are the same thing.
If I had to guess, I would say it were an accidental cross polination (something Nick Woods is already known for, having created the Infinity that way) with the Trinidad Scorpion Butch T. I say this because I also ordered some dried peppers along with the sauce and, while their strong, red, chinense aroma isn't that of any Scorpion I know, they do have both the Scorpion's acidic, orangey fruitness and a Brainstrain-esque 7-Pot fruitness to their scent just the same way the Butch T does. Yet the sauce also warms all the way down in a way that's more tolerable than but still quite reminiscent of the time I ate fresh, homegrown InfiNaga. A unique trait that I associate with chilli-infused drinks and the Infinity side of that pepper.
Then again, while Woody claims not to know what exactly went into the Infinity, I have heard tales that he thought it might involve some Scorpion type so perhaps your theory of it being an early, divergent pheno of the original isn't all that far fetched.