When Chazal argue about a historical fact, for example the size of the mizbei’ach, and only one can be truly right, how are we to understand the concept of “Eilu V’eilu Divrei Elokim Chayim (Eiruvin 13a)?
Eilu v’eilu doesn’t mean that both are always right. It means that both are talking from principles that are true. They are arguing based on true principles and true premises. But sometimes one premise has been taken off on a tangent that doesn’t really apply in this specific case. So therefore, one is wrong and one is right. Yes, one is wrong and one is right.
However, many times it’s only that the hachra’ah min ha’shamayim was to vote for one and not the other. Many times that’s all that it is. But sometimes it’s a fact that one is wrong. There’s no reason why you can’t say that one of them is wrong. There’s no question that the machshovos that led him to his decision were solid and well-founded machshovos. Only that sometimes, in the application of these premises there is a distinction that has to be made and he made an error in the distinction. But Eilu v’eilu doesn’t mean that it has to always be perfectly right on both sides of the argument. No, no. That’s not what it means.