Years ago at one of my old duty stations, I recall speaking with a E-7 who received a Relief of Cause NCOER as a SSG due to sexual harrassment and he was the EO Representative? Is that possible?

Yes its possible. But Officers usually feel the reprucussions more then enlisted soldiers. As you can see your SSG got promoted. That would almost never happen to an officer. You had problems with are Chief once and after the dust settled se screw her entire career up. Also it really depend on what happened. Sexual
harressment is subjective. And something proble everyone could get accused of at least once. ( I'm not saying its right, but it happens.)