A vote justification carries evidence of a strong quorum of nodes all having sent the same message. If a participant receives a justification but has not received those messages, it can treat the justification as those messages. For example, if a node is stuck in PREPARE but receives a COMMIT message, it should be able to use the justification from that COMMIT to immediately complete the PREPARE phase.
A vote justification carries evidence of a strong quorum of nodes all having sent the same message. If a participant receives a justification but has not received those messages, it can treat the justification as those messages. For example, if a node is stuck in PREPARE but receives a COMMIT message, it should be able to use the justification from that COMMIT to immediately complete the PREPARE phase.