The Helianthus experiments were designed to repeat what happened naturally, and they just did that. That, semi-asleep-wideawake is what is called testing a theory. And the answer was unequivocal.
I'll point out that sunflowers have been commercially hybridized for decades before these experiments. The experiment was designed to to create not an atmosphere of natural selection that would create a new, mutated species, but to recreate an existing species from hybridized variants.
The experiment shows that recrossing these hybridized variants results in a "new species" which "is virtually identical to H. anomalus" - I suspect that this new species virtually identical to H. anomalus can actually be cross-bred with H. anomalus and is not therefore a truly unique species.
This experiment tends to show the remarkable phenotypic stability of the sunflower, and does not demonstrate a naturally occurring mutation radical enough to even achieve the level of alteration typical of horticultural hybridization.