Just because he didn't type it in himself, doesn't mean noone did. For advertising it is not needed that you are searching yourself Tracking the Microphone without the approval of everyone that could be heard, wouldn't even be legal here in Germany since DSGVO (and probably the rest of the EU since it's the German implementation of GDPR). What they still can do is tracking what everyone Else searches as well as analyze which Phone ist close by. Are you in the same WiFi range as others? Are you in bluetooth range? Is your Location Data matching? What ist the location you are currently in?

In this case I'd say some of the doctors or nurses searched for it and treated it afterwards, so the phones we're in range often/for a longer period of time. They will now what job they have. Now this guy comes in, they search for saw wounds and then contact him often.