I'm not sure if any one person or organization can or should be the final say on today's question, so I'm putting it out there for the group; maybe we can come to some sort of consensus?
Of necessity this question will take a moment to set up. Bear with.
When two or more people communicate about a certain project they fully intend to embark on, and they have the wherewithal to actually embark on that project, I'd like to think of those folks as "conspiring" to get something done. Especially if during and after their communicating and embarking and accomplishing of said deed, they aren't trumpeting it about to others not in their group. IOW, it's pretty much an insulated or a "mum's the word" operation.
I think a "conspiracy theory" is usually an alternative theory, a reasoning about why/who/what happened that is different than what is commonly held by the majority. That "Oswald did not act alone" started out as a conspiracy theory, but now that most of us feel he could not have possibly acted alone, well, now it's simply a theory.
But.
What if one person, Individual A, acting alone, does something noteworthy and doesn't tell anyone about his or her actions. Only to later have the general view of what he or she did be attributed to a group or an organization, entities not related to Individual A at all. Followed by another individual, Individual B, proposing that the noteworthy event could actually have been dreamed up completely brought to fruition by one person acting alone. Also, Individual B's idea never really catches on... a few people hear about it, a few of them casually nod and say something like: "Sounds possible; I'm not sure what happened though."
Which brings us to today's question. Would Individual B's idea be a conspiracy theory? If not, what would you call it? Keep in mind that Individual A acted alone and did not conspire with anyone.