Sexual abuse and medical experiments on powerless populations have been done to many powerless populations.

No one ever condoned sexual abuse, but we have jus started realizing how commonly it happens in situations where trusted adults are given absolute power over children, with little oversight. Not wanting to admit it could happen is quite different from condoning or encouraging  it.

As for medical experiments, "science" had also been trusted  to do what it deemed necessary without civilian oversight for a long time before it became evident it also needed more regulation.

Neither of those problems are specific to First Nations.