They saw errors related to a deployment, and because it was related to a security issue instead of rolling it back they decided to make another deployment with global blast radius instead?
Not only did they fail to apply the deployment safety 101 lesson of "when in doubt, roll back" but they also failed to assess the risk related to the same deployment system that caused their 11/18 outage.
Pure speculation, but to me that sounds like there's more to the story, this sounds like the sort of cowboy decision a team makes when they've either already broken all the rules or weren't following them in the first place
I'm not sure of the nature of the rollback process in this case, but leaning on ill-founded assumptions is a bad practice. I do agree that a global rollout is a problem.