[outsomnia]

Rejecting a poison message explicitly IS sufficiently processing it.

It's common to have windows in time where two or more sides may not have agreed what happened before they lose communication. Most of the problem can be solved by idempotency, so when the peer retries, the receiver understands it is looking at a duplicate transaction and can discard it indicating that it succeeded.

[pc86]

A message that gets "skipped" - for lack of a better term - because it's already been processed, and a poison message, are not the same thing.