Enola Gay Crew Historians - Lewis Quote Verification

Did Capt. Robert A. Lewis actually write “My God, what have we done” at the time of the Hiroshima mission, or was it appended later? I’m working on a piece that references the dropping of the atomic bomb and I’ve been trying to pin down whether Capt. Robert A. Lewis, co‑pilot of the Enola Gay, actually wrote or said the line “My God, what have we done?” at the time, or if it was something added in reflection later. I’ve looked at the Heritage Auctions listing for his logbook and couldn’t find the quote there, which makes me wonder if it was never actually written contemporaneously. However, I came across this clip of Lewis appearing on the 1950s TV show This Is Your Life alongside Kyoshi Tanimoto, one of the victims of the bombing: YouTube link. Around 15:48 he says, “All I could think of was ‘My God what have we done?’” and then at 17:50, he explicitly notes, “I wrote down later: ‘My God what have we done?’” So it seems clear that he attributed the phrase to his logbook, but it may have been added after the fact rather than at the moment. I’m hoping someone with expertise on the primary sources — the Enola Gay mission logs, Lewis’s papers, or interviews — could clarify: do we have evidence that the line was actually recorded contemporaneously, or is it only from his later reflections? Thank you for any assistance you can offer!