I guess this is the comment chain where we address the room?
I'm seeing a lot of misuse of the word "risk". The FAA prioritizes safety over mission. The mishap that resulted in downtime affected the mission. The common-cause failure of the backup system affected the mission. That is not evidence that they're bad at managing safety risk.
Given that there was an article published at the time about removing the dissimilar backup, it's probable that they explicitly accepted this mission risk.
I'm seeing a lot of misuse of the word "risk". The FAA prioritizes safety over mission. The mishap that resulted in downtime affected the mission. The common-cause failure of the backup system affected the mission. That is not evidence that they're bad at managing safety risk.
Given that there was an article published at the time about removing the dissimilar backup, it's probable that they explicitly accepted this mission risk.