Even granting the abductive characterization, it attaches to ACH-CD (a MITRE counter-deception derivative), not to Heuer's ACH proper

Every description found that attaches "state-based hierarchical plan recognition" to abductive reasoning attaches it to Elsaesser & Stech's counter-deception process — the tool identified as ACH-CD (Analysis of Competing Hypotheses – Counter Deception), a modified variant Frank Stech and Christopher Elsaesser built at MITRE specifically to address cognitive vulnerabilities to deception. ACH-CD is distinct from Richards J. Heuer Jr.'s original ACH. Nothing found — in Wikipedia's text, its downstream mirrors, or any bibliographic record — claims the abductive framing for Heuer's method itself.

This scope distinction is corroborated at Tier 1 by material already in the vault: claim-heuer-grounds-ach-in-cognitive-psychology-decision-analysis-scientific-method establishes, from Heuer's own 2007 writeup, that he grounds ACH in "cognitive psychology, decision analysis, and the scientific method" and never invokes abduction, plan recognition, or Peirce. So even under the most generous reading of Elsaesser & Stech — one still unverified firsthand, and itself resting only on a Wikipedia editorial gloss ([unverified-mechanism — needs primary]) — the abductive-plan-recognition label would describe a downstream, MITRE-built counter-deception variant. It would not establish that ACH proper is grounded in abductive reasoning, and so does not rescue Wikipedia's general lead assertion that "abductive reasoning is an earlier concept with similarities to ACH" (see claim-no-primary-source-documents-ach-abduction-similarity).

This answers the second half of question-verify-elsaesser-stech-2007-ach-cd-abduction ("does it bear on ACH proper?") in the negative, independently of whether the chapter's abductive framing is ever confirmed. It is the ACH↔abduction analogue of the ACH-vs-backward-chaining finding: a structural echo attached to a derivative, not a lineage the method's author ever drew.