Ethical considerations must be given priority when deciding whether or not to include an Alzheimer's Disease patient in a study leading to direct individual benefits. Although the law applies to ethics, the Huriet-Serusclat law was nevertheless written in the spirit of the major ethical declarations of the last 50 years (Nurenberg, Helsinki, Tokyo...) in order to protect patients from abusive decisions, whether these decisions were for or against the patient receiving treatment. This paper describes an incident during a phase II trial involving patients with Alzheimer's Disease. Four incapacitated patients protected by guardianship had given their informed consent to take part in the study. Their participation required that the informed consent be signed by the guardian as well. By misunderstanding of the law, the guardian transmitted the decision to the guardianship judge. Surprisingly, the guardianship judge refused permission for all patients to take part in this therapeutic trial against the wishes of the patients. Even more surprisingly, it appeared clearly that this judge was not thoroughly informed of each detail of the law. Prevention of this kind of situation might require modifications of the responsibilities of the CCPPRB. It is suggested that before the start of a study the CCPPRB should give a precise definition of the way in which incapacitated persons should be treated.