I had a patient recently who came in complaining of feeling tired and worn out for about a week. Just prior to this he had visited his brother in a large city for the weekend. Had done nothing remarkable while there or afterwards, or before or anywhere, had not past medical history, not family history no nothing. I ordered labs which had slightly elevated liver enzymes, but nothing else. He came back in a week feeling better. What did he have? I don't know. Somewhere I missed something, and probably in communicating with him -- not asking the right question or pressing him for an answer. I told him that my best guess was that he had some virus that he was now recovering from, but that I wasn't sure. Did I feel comfortable with that? No, but I didn't have anything better to say and he was getting better. But overall the encounter left me feeling uncomfortable.
Evidency based medicine is good in that it has cleaned out, and continues to clean out a lot of the myths and voodoo in medical practice, but no, it is not the salvation of it as sometimes hailed. The same with double-blind studies. Yes, they are the gold standard, but they are often impossible, for phyical, ethical, or other reasons. Most studies in fact are not randomized double-blind studies. That doesn't mean the information gained wrong or not useful, often not as sure as would be ideal. Still you have to go with what you have and make a decision.
As humans though we want explainable, repeatable answers. To say I don't know, or I don't have a good answer is not seen as satisfactory, or that there must be some deficiency -- and there probably is. But sometimes you don't have a good answer, as in the case of my patient, or CST, or acupuncture, or reiki or many things.