Do you know the difference between a conspiracy "nut", and a rational person?
For a "conspiracy nut", understanding that there is sufficient incentive (also implies a lack of deterrent) for X to do Y is proof enough that X is doing Y.
For a "mainstream" person, that is not enough. They require real, solid proof to consider that X is doing Y.
Note that this is about deciding their own behavior, and not about handing capital punishment for X.
I ll let you decide who is smarter...