I am typically very far from harsh to people. This sort of shit gets under my skin. There are many ways to post something here without getting negative opinions, it is done all of the time.
Now you took a word of mouth story from a friend who is some how qualified in their industry, claimed you did some Government fact checking on it (another source is always good) and then posted the facts that you concluded.
Needless to say you are or should be an "Internet specialist" so you should know about such BS claims. Therefore you should know to post some link to your Government information. You should research it some and not be quick to just spread it even more.
Before I even jumped your shit, I went and did a very simple Google search for keywords
Cadbury hoax. Walla, real facts.
Before any high horse is climbed on or what not. I am what they call infirm or at risk for such things. It is not that I do not give a rats ass about kids. I just also can see a larger picture, one that is gruesome. People believing you without even checking for themselves and spreading this lie even further.
You talk about caring for people. What about the owners of that company, what about the people that work there, what about their kids, what about the stores that may not sell their merchandise due to such hoaxes. Specially in a critical time of the year when many candy companies make a good portion of their sales.
Odds are you had the best intentions, though as the saying goes. The path to hell is full of good intentions. So think about reactions and others outside of your world and try to include everyone else's.