1. Effective communication of a protocol has no relevance to its efficacy. So that's a plainly unscientific test of the 'truthiness' of anything.

2. No phenomenon ever, scientific or not, can be guaranteed to be stable in the face of all 'unknown' factors. They are unknown, you cannot make any statement about that.

I understand where you are coming from, but that puts you right in the middle of the philosophical quagmire mentioned in my earlier comment. If you mean 'variation in people performing the experiment' by those 'unknown factors' then essentially you are making the assumption that the people are not a factor that is expected to influence the result. As such, even the same team repeating the experiment would suffice. Anyway, you get the point.