The stability of it is the giveaway. It's not a meta-stable failure state, it's a fully stable failure state. There is positive feedback; increased latency on a link begets further link usage; which causes more latency, etc.
Had there been some kind of negative feedback (in the electrical engineering sense of the word) and this still happened somehow it might be a lot more difficult to track down. But introducing negative feedback is what they did to solve the problem, so perhaps it wouldn't have still happened.