Is the Filter Theory committing the ad hoc fallacy and is it unfalsifiable?

Interesting link.

My information comes from How Not to Do Survival Research: Reflections on the Bigelow Institute Essay Competition p368.  He references his source as (Holden, 2009, p210). 

Your link comes from Explore, which is a journal that has been highly criticized for not meeting scientific standards. Your link says it includes more studies than the only previous meta-analysis, which probably is a reference to the Holden study. I suspect that the Explore meta-analysis includes a number of controversial studies that the other study excluded. There is a lot of published literature on mediums that is not reputable.

How about looking at the other side of this argument by a notorious closed-minded skeptic:

Not So Fast: A Response to Augustine’s Critique of the BICS Contest

Stephen Braude, Imants Barušs, Arnaud Delorme, Dean Radin & Helané Wahbeh

Journal of Scientific Exploration 36 (2):399-411 (2022)  Copy  BIBTEX    (https://philpapers.org/rec/BRANSF-2)

Abstract
Keith Augustine’s critical evaluation of the essay contest sponsored by the Bigelow Institute of Consciousness Studies (BICS) is an interesting but problematic review. It mixes reasonable and detailed criticisms of the contest and many of the winning essays with a disappointing reliance on some of the most trite and superficial criticisms of parapsychological research. Ironically, Augustine criticizes the winning essays for using straw-man arguments and cherry-picked evidence even though many of his own arguments commit these same errors.

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And you had better back up your generalized claim that the Explore meta-analysis includes a number of "controversial" studies (maybe trashed by notorious closed-minded skeptics?) that you accordingly automatically presume worthless as evidence, with some plausible detailed arguments that the dismissed and referred to studies are really worthless as evidence. 

Or the claim is just closed-minded materialist speculation.