It's been like 10 years since I worked in the space but I'm pretty sure showing adsense on search results like that has been against the tos for a very long time unless you get a specific search feed(which is basically impossible these days and even 15 years ago was limited to companies like ask.com)
Interesting. It seems like a ToS violation would have been worthy of a warning and revoking the offending earnings, but nope, it was no mercy or review.
Sounds like a footgun waiting to go off? Unless Adsense is pretty explicit about this, beyond some language buried in a TOS.