They knew he was special when the intern smiled at their scornful "sweetie." The tone surely could not have gone over his head. He went to a top university, after all. He smiled at what other males would call micromanagement.
To make sure of this, they engaged in a several-day intern swap. One run mostly by male lawyers, and one mostly by female lawyers. He got up to speed much more quickly with the second. "How was it, sweetie?" and "If you'd rather not be called sweetie, let us know."
He never did. He was obviously capable but not fit for more overtly masculine environments, and it would be all for the best if they said so in their recommendations. They knew other powerful women in charge of big law firms, of course. They would direct him that way, once he graduated from law school. They wanted the best for him in his career.
There should be no shame in males preferring to work for females these days. It was happening more and more.