How did a tool roll out changes to extra regions by accident? Fat-fingering a larger than intended volume in a single region I get, but does their tooling not r

How did a tool roll out changes to extra regions by accident? Fat-fingering a larger than intended volume in a single region I get, but does their tooling not require explicit opt in for regions? Why does it even allow simultaneous multi-region rollout at all? Is there no auto rollback, or was the failure mode not something that was a considered side-effect of the system?