In distributed system terms, this is a byzantine failure which most consensus mechanisms are not equipped to handle.
The problem is really that many formal proofs of consensus have focused only on the network fault model, and neglected the storage fault model.
Both network/storage fault models require practical engineering efforts to get right. I think a better term for this is “near-Byzantine” fault tolerance. It's what non-Byzantine fault tolerance looks like when implemented correctly in the real world—the GP comment is a great example of how to approach and think about this from an engineering perspective.
I dive into this in detail also here: https://www.youtube.com/watch?v=rNmZZLant9o
You don't call plaintext SMS "tamper-resistent" because it resists to some simple tampering. You don't call your house "FBI resistant" because you managed to convince them once to turn around.
A Byzantine fault is clearly defined as a case where a specific node may be doing anything, including not know it has failed, including malicious behavior. It is important that people know what class of faults their system is designed to resist; for Raft/Paxos, it is NOT Byzantine faults. Those systems are pretty great, but trying to pretend they aim at BFT is dangerous misinformation...
Remember that the Byzantine generals had traitors among them, not merely communication issues.