The Horde fleeing could mean that. Or they could have been routed given the massive slaughter (over a million corpses there, mostly Scranc, as noted) with the Quya pushing them out of the Canal.
Sranc routed? Really?
EDIT And in silence?
Sranc can be routed, they were driven across the large of the Istyuli plains before being forced to fight at Dagliash. As far as the silence, relating to the Canal just being cleared and those outside running. It wasn't literally silent so much as the contract from before. At least that's how it read to me.
I assume SmilerLoki is referencing the fact that The Boding is not described until after the births. Which might be fair, given that apparently everyone around the world could feel it. It seems quite a significant horror. Not that I think that is conclusive proof otherwise either.