We report the first case, to our knowledge, of amatoxin hepatotoxicity in Iowa and explore the ethical and decisional challenges of offering an investigational treatment of a rare disease. Acute liver failure due to ingestion of amatoxin-containing mushrooms is a relatively rare entity. Once amatoxin poisoning is identified, there is no clearly effective treatment, leading to a broad range of theoretically beneficial, anecdotally successful, or investigational options. The evolution of hepatotoxicity led us to offer investigational treatment with silibinin, an extract of Mediterranean milk thistle. We explore the pitfalls in medical decision-making experienced by both the patient and the physician in the face of ambiguity. The patient did well following silibinin infusion, but we are left uncertain as to whether the patient truly responded to treatment or was simply destined to recover.