Network management software complexity is supposed to be one of things that SDN was built to solve (by introducing more modularity and defined interfaces). But

Network management software complexity is supposed to be one of things that SDN was built to solve (by introducing more modularity and defined interfaces). But in this case the fault was at the edge with BGP route updates, which the internet has been doing for decades. I share your curiosity in the specific bug. However, this is a great detailed post-mortem from a service provider. Your Telco or ISP will never provide this much detail...