In this case, intent has no bearing on its utility.

What should guide the rhetoric of social movements is, to take it back to your college GE writing class, the consideration of "writer-based" vs. "reader-based" writing. In the former, you write what you feel based on how it makes sense to you; in the latter, the intent of the writing is to convey a message in the way that the audience can comprehend it.

That hashtag will and does imply "the accused is guilty." Something that would convey the intent you describe more directly would be along the lines of #DismissNoWomen or #TakeHerSeriously.