"The CSC is pivotal in determining the course of action after the SSRA; however the actual SSRA is done by the DSMB. The DSMB is the only group who has access to the unblinded data. After the SSRA the DSMB makes a recommendation to the CSC on the course of action."

That is consistent with my previous understanding of the relationship between the CSC and DSMB, as well as my previous understanding that the independent DSMB is the group who performs an unblinded SSRA, not the blinded CSC . But as I acknowledged over the weekend in response to DND, a blinded SSRA could potentially be done by the CSC or the DSMB. I'm not sure how you phrased your question to Sarah, but her response makes it look like they would do an unblinded SSRA.

BearDownAZ