Hallucination control is one of the most critical dimensions of AI reliability in professional contexts, because errors rarely appear as obvious falsehoods and instead surface as plausible, well-structured, but incorrect assertions  that can silently propagate into documents, decisions, or external communications. In this comparison, Claude Sonnet 4.5  and ChatGPT 5.2  represent two distinct philosophies of factual reliability, one centered on preventive restraint , the other