Testosterone in utero is simply one period of exposure, during infant/childhood development the differences between the sexes on testosterone exposure can be vast.
It comes down to this, the claim of "equality" is reflected no where else in nature, and does not fit evolutionary theory.  So onus has always been on those making the truly extraordinary claim of equality to prove their case, not the other way around.
At this point the quibbles which continue to fall away as we discover more simply remind me of the "god of the gaps" defense of the creationists.

And really, the left should reconsider their attempt to make all things the same, when their entire basis for gay rights was "born this way".