I would have thought maybe it was caprified, but caprified Panache at USDA/UC davis look normal.
I am guessing it was just mutant, and probably not capturable. Other fruit on same branch are normal, so I doubt it is genetic mutation in the wood, which could be propagated. As opposed to Reverse, which is Panache which had reverted back to its original all green color.
Nice looking fig, however.