Isaacs's recorded regret in Pesch & Plail's 'missed opportunities' survey is over dismissing his own 'tenet of transition' — not the 1963 Pontryagin near-miss

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Pesch & Plail's 2009 survey of optimal-control priority (Control and Cybernetics 38(4A)) carries a section titled "Regretted and claimed 'missed opportunities'" — built to cover exactly the terrain where Isaacs's priority consciousness relative to Pontryagin, Bellman, and Hestenes would be expected to surface. What it records of Isaacs is a different regret from the one his preface frames. Quoting Isaacs (1973), p. 20, it prints his account of under-rating his own "tenet of transition" — first feeling it was "the heart of the subject," later judging it "a mere truism," and so giving it only a title in the book: "Thus in (my book) "Differential Games" it is mentioned only by title. This I regret. I had no idea, that Pontryagin's principle and Bellman's maximal principle (a special case of the tenet, appearing little later in the RAND seminars) would enjoy such widespread citation." The regret is over dismissing his own idea, not over the days-margin near-miss on Pontryagin's book that his 1965 preface records.

Neither the 2009 survey nor its near-identically worded 2012 companion (the same two authors, one Cold War narrative in two "corners") mentions "a few days," March 1963, or Isaacs narrowly missing Pontryagin's published book. This extends the single-witness finding from a weaker absence to a stronger one: the earlier search found only that two biographies (MacTutor, INFORMS) omit the episode; this is a dedicated "missed opportunities" treatment, by historians who went looking for exactly this kind of regret, that records a different Isaacs regret instead. It is absence, not disproof — and it is not an independent witness: the regret quote is Isaacs's own voice via Isaacs (1973), and the two surveys reduce to one root (Plail's 1998 monograph). It also sharpens the vault's existing observation that Isaacs's record carries more than one sense of "first" against Pontryagin. The corroboration question stays open at question-verify-isaacs-pontryagin-1963-near-miss-corroboration.