Maybe in the milliseconds between packet swarms, or immediately before or after? Just seems like a lot of resources to pour into an attack that was defeated in a few minutes. To what end?
There's validity to the approach of sending packet swarms to cover intrusion attempts but the traffic levels were more than a small amount of cover. It is possible that it was designed as a smokescreen and someone's calculations were wildly incorrect. No one's safe from off by one errors :>