False positives with data removal services?

A few months ago, I started using EasyOptOuts and Google’s search result removal service. Eventually, I received an email from EasyOptOuts with a list of sites my data was (supposedly) found on. This included some that I thought I remembered searching manually many months before. When I did my manual search through the list of data brokers PG had at the time, I remember only finding one that had a significant amount of data on me. Another had just my name and phone number.

I also began using Google’s search result removal service, and I sometimes receive updates on places it says it’s found my information. But I took a look at some of those sites myself and didn’t find anything.

Does anyone know why these services might say they’ve found my data on sites that don’t actually have it?