Hirsch modeled his CSH-fraud critique on a 2009 Debessai et al. europium paper he argues is a confirmed precedent case of data alteration

research-integrityfraud-detectionphysicssuperconductivityhirschdebessai

In his own peer-reviewed Physica C paper, Jorge Hirsch argues that the one sample of "raw data" Ranga Dias and coauthors did publish for the carbonaceous-sulfur-hydride (CSH) claim behaves in a way "completely contrary to what is expected for a superconductor" — and that it closely resembles, in shape and magnitude, the raw data underlying a separate, earlier claim: a 2009 Physical Review Letters paper reporting superconductivity in europium, led by Mathew Debessai (ref. 10 in Hirsch's numbering), a co-author of both the 2009 europium paper and the 2020 CSH paper. Hirsch reports having obtained the actual measured data behind the 2009 europium result and, on that basis, states that "the evidence of Examples 1, 2 and 3 discussed above establish unequivocally that extensive data alteration and manipulation occurred in going from measured data to published data for Fig. 2" of the europium paper.

Hirsch explicitly uses this earlier, better-evidenced case as his working model for what he believes happened to the CSH data — but he is careful to distinguish the two: for CSH itself, absent the raw data at the time of writing, he states he "cannot prove beyond reasonable doubt that fraud was involved." The claim of alteration in the 2009 paper is Hirsch's own conclusion, published in a peer-reviewed venue, not an independently adjudicated finding; no third-party body is known to have ruled on the 2009 paper specifically. The 2009 europium paper did not stand, however: Hirsch's paper itself notes (Sect. XI) that the authors informed Physical Review Letters on 27 July 2021 that they might retract, and they did — the five authors retracted it on 23 December 2021 (Retraction: Phys. Rev. Lett. 127, 269902). An authors' retraction corroborates Hirsch's analysis by the authors' own action, while still falling short of a misconduct-body adjudication.

Debessai is the physical link between the two datasets: per Hirsch's account, he performed the underlying susceptibility measurements for both the 2009 europium and 2020 CSH studies, and taught Dias high-pressure technique. See claim-hirsch-van-der-marel-2022-csh-data-pathological-spline-quantized for the specific statistical mechanism Hirsch and van der Marel later applied to the CSH data itself, and claim-hirsch-forensics-drove-dias-superconductivity-retraction for the retraction outcome this critique helped force.