In the "Advanced Ethernet Configuration SAOS 6.17" manual on the "Ethernet Ring Protection switching configuration" chapter a recommendation is made to never let an interconnection node (a node that connects a sub-ring to a major ring) be an RPL owner:
"Create virtual rings to optimize usage of all links in a logical ring. You can create multiple virtual rings on the same logical ring by using different RPL owners. For this reason, it is recommended that the RPL owner not be assigned to an interconnecting node."
"In sub-ring implementations, do not assign the RPL owner to an interconnecting node. If the RPL owner is assigned to an interconnecting node, faults on the sub-ring can prevent traffic flow to a node between the sub-ring endpoints."
I do not understand the highlighted warning above.
In the attached diagram from the manual, how could letting interconnection node B be the RPL owner for either the sub-ring or the major ring prevent traffic from flowing between nodes C and E during any single link failure scenarios?