Interesting. My understanding was that IMEI could be traced to what vendor it was sold to, then they could pull the purchases and either see the card used to buy it, or find the video when the transaction occurred. Guess it depends on whether there is a method to pin which the exact phone without needing to scrub the purchases records.
You are significantly overestimating the level of recordkeeping by random sellers of used and/or ultra-cheap phones. Manufacturers, major retailers, and carriers may keep this information, but bodegas and street vendors certainly do not.
This is certainly approaching murder investigation levels of effort by law enforcement, but I don't think it's ridiculous to imagine a POS system being used that keeps transaction records for a year or two.
There are so many links in that chain that need to line up, from the manufacturer keeping track of it to the distribution system to keep track of what batch goes where to the vendor keeping track of what phone IMEI is sold when or to who. Even if all those link up you need to get at the video within the rotation time for their video storage or link to their financial transaction data.
I would not be surprised if it is still as easy to evade as shown in the show (and as easy to get wrong).
