They couyld have indeed presented data that only AIs would scrape or notice... which would be entirely legitimate on their part to do.
My own website spews bogus content and misinformation about almost any topic to misconfigured scrapers. I expect to eventually see it in some training sets.
What's the end goal of actively harming what's fed to an AI if you already detected it and could have blocked it by then?
How would one implement that?