Not enough information.

But I recall years ago the ATC system made heavy use of multicast in ways that scared me. I dunno if that stuff is still out there but it was some real I wouldn't do that shit if I were you stuff. And yeah mcast can sure fuck a network fast.

As for in general there's plenty of ways a single box can melt a network. Routing protocols let you do bad things fast and pull in more traffic than you can eat.

I mean, if rookies are in charge of the plan then sure. It’s the network engineering equivalent of a pilot ignoring all standard safety checks and a flight plan.

TL;DR of my top-level comment: Yes, but only if the work was done by clowns. ;-)

Do these routers not have rate limiting on them, and if not why in the world not? Sounds like a route loop that then spread out to the rest of the network.