The record
In a September 1972 letter Lewin reported both tremolite and chrysotile present in Italian 1615 talc, at “just at the minimum level of detectability”, using the protocol the FDA was then tentatively considering as its official procedure.
Claim scope
That by September 1972 the detection-limit problem was explicit in the primary correspondence: positives were being found exactly at the threshold of the method's sensitivity.
What this source does not establish
Whittaker/Old Spice supply chain, not J&J.
Limitations
McNeal is the most valuable opinion in this set for timeline purposes because the court sets out the internal documents in an explicitly dated month-by-month chronology (headings 'a. August 1971' through 's. May 1977'). CRITICAL COUNTERWEIGHT: the court REVERSED the punitive damages award, holding the same evidence did not establish malice, oppression or fraud. Any use of McNeal must carry that disposition. The documents are verified as recounted; the culpability inference was rejected by this court.
Source
Case Citation — McNeal v. Whittaker, Clark & Daniels, No. B313472 (Cal. Ct. App. 2d Dist. Div. 8, July 5, 2022) (published; reporter cite UNVERIFIED)