You don't believe in the so-called "absolute truth of the word of Vishnu."
And you have no reason to be sure that the flutes in Germany are 42,000+ years old.
So it sounds like you are taking claims that are not absolute and shouldn't be used to evaluate other claims, and putting on the same level as the Bible, which does claim to be absolute, and does claim to be a standard by which other claims can be measured.
Therefore, your evaluation the Bible starts out assuming it is something less than it claims to be. This is a strawman argument.
The reasonable thing to do would be to consider the Bible as it really claims itself to be, even if just for the sake of argument, and see if that leads to inconsistencies.