Pangram 4 Reports a 0.0041% False Positive Rate on AI-Text Detection, Two Orders of Magnitude Below Typical Classifier Claims

arXiv 2607.27183 (Pangram Labs)·medium signalXBlueskyLinkedInCopy link

The July 29 technical report (arXiv 2607.27183) from Pangram Labs claims AUROC 0.9916 with a 0.0041% false positive rate and 0.3396% false negative rate, plus better out-of-distribution generalization and adversarial robustness than Pangram 3. The novel contribution is fine-grained discrimination of edits and mixed AI-human co-writing rather than binary authorship. The FPR is the number to scrutinize — it is the figure that determines whether detection can be used punitively at scale, and it arrives the same week a NeurIPS reviewer reported receiving entirely LLM-generated rebuttals.