In this scenario, when both an Active SAM and its corresponding BIM fails, then both Standby SAM and BIM becomes active. This scenario is illustrated below:
All components are up and running. Active BIM talks to Active SAM and vice versa. Similarly, Standby BIM talks to Standby SAM and vice versa.
Both Active SAM and Active BIM are down.
Standby SAM and Standby BIM become Active.