Hmmmmm... interesting. I could see how acacia might have tripped them up as there are so many grades of it.
As much as I find it an interesting experiment, I'm more than a little skeptical that it tastes anything like coke.
I'm quite certain that companies with more resources than these two women and their friends have attempted to duplicate coke. If a company with access to vast taste testing focus groups and laboratory equipment can't re-create coke, I don't see how a handful of people can.
This type of "if I think it tastes like the real thing, then is MUST taste like the real thing" runs rampant through the copycat community. And it doesn't do it much service. Re-creating commercial products is a lot more complicated than throwing a few ingredients together in a kitchen- with or without the presence of a scientific advisor.