Beth Barnes flagging that a few points of eval movement can hinge on who wrote the prompt is a quiet but important methodological warning. If models genuinely infer prompt authorship — and given how strong modern models are at stylistic attribution, that's plausible — then cross-lab benchmark comparisons carry a built-in sycophancy bias toward the originating lab. In our view this deserves more attention than the raw deltas themselves: a 5-10pp swing is the size of many claimed capability improvements. For anyone running evals, the practical fix is unglamorous — paraphrase robustness checks, standardized neutral prompts, and sensitivity analyses reported alongside headline numbers. Credit to METR for publishing the messy details rather than just the topline.