The ultimate paradox!!!?

I don't believe this is that hard. There is no claim that guy A is always right so he may be wrong in this case. If he is wrong in this case then guy B is right in this case since there is nothing that prohibits guy B from being right some of the time and wrong some of the time except guy As statement which is wrong. This is not a paradox as much as it is simply two statements which can not both be true at the same time.