A 52-year-old man with hypertension presents to a private clinic with chest pain. The physician, without performing any investigations or physical examination, prescribes aspirin and sends him home. The patient suffers an acute myocardial infarction that night and is admitted to a hospital with complications. The patient's family now wishes to pursue legal action against the physician. What is the most appropriate first step the physician should take to protect himself legally and ethically?