I run a business dealing with used games retro games consoles, and a not-insignificant part of this involves buying and selling faulty items. E-waste chains, especially for devices like iPads and PlayStations, are ridiculously complex, international and informal.

Honestly wouldn't be surprised if the thief here really was just a chav on a bike that flogged the phone off cheap to some guy he initially met on Facebook Marketplace. That guy probably paid a couple of quid to some random in India to attempt to unlock the phone remotely (without telling the buyer how he does it), and when that failed it would have been shipped to a contact in China who the buyer knew paid $x for a iPhone with an uncracked screen.

Also interesting to see the difference in culture. In Australia, if you lose your phone (almost always from falling out of your pocket, I've never really heard of anyone having theirs stolen), you just call it every couple of hours until the person who found it picks up. Then, you fling them a bit of cash or booze when you go to pick it up and everyone's happy.