A 38-year-old male presents to a psychiatric clinic requesting documentation of disability for a pending workers' compensation claim. He reports hearing voices that command him to hurt others, visual hallucinations of demons, and an inability to work due to his symptoms. He describes his hallucinations in elaborate detail and states they began immediately after a workplace injury six months ago. During the clinical interview, he is observed to be evasive when questioned about symptom specifics, and his affect is notably incongruent, smiling while describing terrifying hallucinations. On structured testing, he endorses an unusually high number of rare and atypical symptoms on the Structured Inventory of Malingered Symptomatology. Which assessment finding is the strongest indicator of possible malingering in this presentation?