The reality is: Unless he fled the country he was always going to be caught. That is the point of living in a surveillance state. It was just a matter of time.
As a thought exercise, imagine a bathroom. Ten people go in. One person flips their jacket inside out. Ten people come out. Do you suddenly lose that one person who now has a green jacket instead of a red one? No. You realize the person with a green jacket never "entered" and know something was up.
And now extend that to every single traffic camera, security camera, and so forth in the city and in the country. Because now that "bathroom" is a camera at every major exit in and out of Central Park as well as places where the shrubbery is low enough that you can hop a fence.
And yes, that is a VERY large amount of data. If only we had spent the past few decades learning to represent things as graph problems, how to use computer vision to automate recognition, and so forth.
It was obviously dramatized (and is fascinating from a production standpoint and how much effort they put in to keep the nazi from killing anyone...) but Person of Interest wasn't some dystopic future. It was, if anything, underestimating what is already possible.
So... here is hoping that ridiculously handsome G went straight to the airport and flew to a non extradition treaty country. Probably didn't though and is probably going to get picked up at a bus station.
Also: For all the gun nuts who think you rae going to use your closet full of AR-15s to scream "WILDCATS" and fight off the fascists or invaders or whatever? They'll have access to those cameras too and will be able to figure out what house or cave you are hiding in and send a few drones. So... yeah