"From his expression I guess he knows it's a big deal, but just didn't know what to say."

In my experience this is case with most disclosures to non-survivors. They know how they are supposed to react, they genuinely believe what was done to us was heinous, but they simply do not know what to say or do. My own doctor suggested I "bury it because this is something that can really hold you back," which really just made me wonder what he had to bury in order to become a doctor. All in all he probably genuinely means what he said to you but he likely has no idea just how meaningful hearing that is for a survivor.
"Life is like this dark tunnel. You may not always see the light at the end of the tunnel, but if you keep moving, you will come to a better place." ~ General Iroh