A 48-year-old woman is enrolled in a double-blind, placebo-controlled RCT evaluating a novel statin (Statin-Z) for primary prevention of coronary artery disease. She is randomized to the Statin-Z arm and receives the active drug. At 6 months, she develops severe myalgia and is diagnosed with statin-induced muscle injury (confirmed by elevated CK levels). The trial protocol mandates that all adverse events are reported to the Data Safety Monitoring Board (DSMB), but the treating physician decides *not* to report this event because he believes it is unrelated to the study drug and does not want to 'bias' the trial results. The patient continues in the trial. Which of the following is the most serious ethical and methodological consequence of this action?