Delta's position is the Microsoft actively recommended and coordinated with CrowdStrike to the extent that they are co-responsible for outcomes. In a large enterprise like Delta, the vendors do work together in deployment and support. Yes, there's often a great deal of finger-pointing between vendors when something like this happens, but in general vendors so intimately linked have each other on speed-dial. It would not shock me to learn that Delta has email or chat threads involving CrowdStrike, Microsoft, and Delta employees working together during rollouts and upgrades, prior to this event.

As far as refusing help, why is that funny? If someone does something stupid and knocks you down, it's perfectly reasonable to distrust the help they offer, especially if that help requires giving them even more trust than what they've already burned.