Some of our customers noticed Inter-1 (our omni-modal social-signal model) would occasionally "hear" a quote that didn't exist. Feed it a video with zero audio and ask what was said, and it would sometimes report: "Yeah, Friday at five." Verbatim. Same line, every time. We assumed it had to be baked into the training data somewhere, so we went looking everywhere: 30,960 training records with datetime mentions → zero hits on the phrase 4,603 video transcripts → zero hits ~800 inference probes, 584 storage objects → zero hits Turns out the phrase was sitting in our own system prompt — a worked example we'd written to show the model the expected output format, buried in a version our GEPA prompt-optimizer had shipped. But that only explained where the words came from, not why the model woul...