So this nonsense has hit the food bloggers, I see. We've been dealing with threats like this from the "big guys" for years in handcrafted toiletries and soaps. The "big guys" would target a handcrafter with threats such as law suits if the crafter did not cease and desist using the formulation/product that the "big guys" found objectionable. The homecrafter is usually found by the "big guy" who uses a web search program that target key words. I'm assuming that's how this food blogger was found by CI.
We've always intrepreted the law as that, if a formulation or recipe is altered by at least 10% (ingredients or process), then it becomes a new "original" formulation/recipe. Like cooking, certain things are basic common knowledge - fat + lyewater = soap, oil + water + emulsifer = lotion etc. But its the use of unique ingredients, the change of percentage of ingredients or the way they are combined that makes your formulation unique.
And we learned the hard way over the years, if you want your formulation/recipe to stay proprietary, do not publish it on the internet or give it to inquiring minds! I know if I do a web search for "bohunk's #13 self emulsifying body scrub" I'd get a gazillion hits and find a gazillion recipes that use my original but are modified to be "unique" to the new author (exeragation of course). There are some recipes I'll never share because of the work that went into them and they were the backbone of my little business such as my oil-free body wash and lotion formulations. Nor do I share my oil percentages for my bar soaps. But on other occasions I have shared formulations like my self-emulsifying body scrub because we were all trying to crack that nut and I happened to put together one of the first decent ones and I wanted to give back to all who helped me with input and I knew crafters would take the basics and fly with it and make their own changes to make their own unique scrub.
The upshot is, yeah for this blogger standing up to CI and shame on CI. Bully tactics should never be tolerated.