Given Adela's actions during the trial, she was not right in her accusation of Dr. Aziz.
The reality is that once she changes her testimony and recants, Adela stops the machinery that she herself started. In this regard, it becomes clear that she was not right to accuse Aziz. Once she changed her mind, everything becomes the proverbial "muddle" that is so much a part of the novel.
However, when we have to debate issues of "right" and "wrong," it presumes a level of certainty. The fact of the matter is that we really don't know what happened in the cave. Therefore, we don't know if Adela was right or wrong. We know that Adela came to terms with some intensely powerful realities. For example, we know that she understood that she did not love Ronny. We also know that the force of the cave exploration itself was real and quite authentic. However, what exactly took place at the caves is never answered in the trial, or in the book for that matter. We are left with a "muddle."
Given this ambiguity and doubt, it becomes difficult to judge whether Adela did the right thing in accusing Aziz. The only reality that we are left with is that she recants her accusation. She plays the critical role in stopping the trial that contained a vested interest for so many. The rationale behind why she changes her testimony is never really known. We simply know that she stops what she started. In that regard, her actions can be seen as wrong. Which exact part is incorrect becomes the "muddle" that Forster ascribes to India, in general.