The cosine-0.85 pairing between ChainQueen's Sulsky/Schreyer citation and Ansari's Contamination Inheritance finding is a hedged bridge — opposite citation polarity at the referent, a real asymmetry-in-evidence at the method level

citation-analysiscitation-copyingcontamination-inheritancematerial-point-methodchainqueenbridge-investigationhedged-bridgebibliometricshistory-of-computingcopy-fingerprint-test

Seek's semantic index flagged claim-ansari-2026-contamination-inheritance-citation-error-propagates-across-models and claim-chainqueen-reference-list-directly-cites-sulsky-zhou-schreyer-1995-mpm-origin as a bipartite pairing at cosine 0.85 [unverified-quant — needs primary; the figure is the task framing's]; vault_bridge separately returned bridge_candidate: true. No capture in 10-inbox/raw/ previously named both slugs together, and no existing vault note adjudicates this specific pair.

At the referent level the two are opposite in kind, not variants of one mechanism. Ansari documents a failure: a fabricated citation ("Z. Zhu, T. Yu, X. Zhang..." for a nonexistent "Neuralrgb-d" paper) that a NeurIPS 2025 author's LLM reproduced because an earlier preprint (Beltran et al., v1) already contained the identical fabrication before a later version corrected it — "the hallucination may not have originated with the NeurIPS author's LLM but was instead inherited from contaminated training data." ChainQueen's case is the reverse: its reference [9] correctly and directly names the Material Point Method's real originating lineage, Sulsky, Zhou & Schreyer (1995), transcribed down to volume and page numbers — a citation working exactly as citation is supposed to. The cosine is plausibly matching the vocabulary shape "citation... traces/inherited... origin," not shared referent — an embedding false friend at the object level.

One real asymmetry survives past that verdict, at the level of evidentiary method. ChainQueen's attribution does not rest on the citation alone: the vault's own note on it is independently corroborated outside the citation chain by SAND-91-7095 (OSTI catalog year 1992) and Schreyer's own faculty bibliography — a second, non-citation leg. Ansari's Contamination Inheritance finding has no such second leg: by the paper's own account it is "identified in at least one case in our dataset," inferred from a single identical-string match, with "training-data audits, version-controlled corpus tracking, and citation genealogy mapping" named as future work the paper itself did not perform — whether a direct read of the Beltran v1/v2 diff would convert this from a one-text-match inference into a directly observed correction remains open, see question-verify-beltran-2024-v1-v2-diff-confirms-ansari-contamination-inheritance. Applying the vault's own copy-fingerprint test (via Simkin & Roychowdhury, 2002) sharpens why: a correct citation carries no fingerprint and needs none here, since ChainQueen's claim is independently settled; Ansari's claim is the fingerprint, and it is the sole evidence available for it. The test, first used in this vault to contrast Ansari against the uncorroborated Kwakernaak-1977 trail, now contrasts it against a corroborated case instead — sharpening its scope to: it matters only when citation-chain evidence is the sole evidence in hand.