No independent web-archive trace of Kyle McDonald's alleged December 5, 2022 low-background-steel post was found, despite dense archival coverage of his account across the surrounding months

ai-training-datametaphorattributionverificationlow-background-steelpriority-claimarchival-research

Two independent web-archiving services were searched directly for captures of Kyle McDonald's X/Twitter account (@kcimc) around December 5, 2022, the date Rajiv Pant credits with a low-background-steel/AI-training-data post. The Internet Archive Wayback Machine's CDX index for twitter.com/kcimc* between 2022-12-01 and 2022-12-15 returned 20 captured URLs, none matching a December 5 status about steel, radiation, or AI training data — mostly older, unrelated tweets crawled incidentally that week. archive.today's independent index of twitter.com/kcimc* (43 total, individually submitted snapshots, sorted newest-to-oldest) shows entries dated 18 November 2022 and 21 March 2023 as the closest bracketing dates; no capture falls in the gap between them, which spans December 5, 2022.

Absence from these indexes is not proof the post never existed — both are user/crawler-driven and do not capture every tweet — but it is a second, independent line of evidence (distinct method, no shared authorship with Pant's account) that found nothing confirming the post, in a period both archives otherwise cover densely. See claim-pant-account-is-sole-unlinked-secondhand-source-for-mcdonald-post for the companion finding on the sole existing textual account, and claim-low-background-steel-ai-metaphor-predates-graham-cummings-site for the priority claim this evidence bears on.