What you are saying is not what they are saying at all.
Many of the Nazi medical experiments talked about were in the same ballpark of what was disclosed here. They occurred along with the euthanasia and genocide but weren't the euthanasia and genocide itself, they were different.
As for your last sentence, of course not - it would fall under a completely different type of law that war crimes... I don't know if they were charged with anything but they should have been charged with crimes under US criminal law.
The white house apologized and acknowledged Tuskegee, I did not read that they eventually recognized it was comparable to the holocaust. Did Clinton affirm that? Did he give a specific example how it was similar?
The full extent of Nazi medical experiments was not limited to mass murder and included things akin to what was done with Tuskegee so your question seems either deliberately in bad faith or something you could answer yourself with a bare minimum of research