It could have been something as simple as politely asking the ISP or the police. Given some of the circumstances which transpired and how difficult it may or may not be to get the ISP to give you the street address, I wouldn't be surprised if they went, or at least tried, that route.
Keep in mind he translated three ip addresses into street addresses and two of them turned out to be public hotspots.
I doubt asking kindly would yield personal information. This kind of social engineering can be used for bad as well and I'd doubt they'd leave the justice and investigative powers in the hands of a citizen.
Keep in mind he translated three ip addresses into street addresses and two of them turned out to be public hotspots.