Event ordering violation from producer retries

A state-machine service consumes a Kafka topic where per-key event order matters (account_id key to created, updated, closed). Support finds a few accounts where a closed event was applied before an updated event for the same key, leaving stale state. Consumers are fine and in order. Investigation points at the producer: it's configured acks=all, retries=10, max.in.flight.requests.per.connection=5, and enable.idempotence=false. Dashboards show a brief network blip to the broker ~around the affected timestamps causing some produce retries. Triage and explain how events got out of order on the same partition.