This would only be the case contextually. So, it loses practical argumentation purpose. If someone were to have obvious evidence of deity, and I did not, it would not change the fact the person had evidence, whether I was arare of it, could prove it, etc. So, what we are actually doing, is making conclusions drawn from most probable, and even what we have a proclivity to. One of the problems with a broad atheistic stance is that it is actually difficult to support in the face of the statistical possibilities that all the theists who believe they have evidence, is incorrect. Explicit atheism , for example, would be pretty difficult for me to justify, considering the data and parameters for probability that I employ. Certain deity concepts, that's easier, but even that is problematic. It's like when people on the net say something like, ''that image is scarred into my brain'', etc, .lol. Once any evidence contrary to explicit atheism, or I would call it materialism, /as atheism isn't tenable imo/, it is almost impossible to come up with alternative 'certainties', and very problematic for alternative 'possibilities, as well. It can be done, but there is nothing inherently more probable with these alternative theories.