diff --git a/pkg/kgo/producer.go b/pkg/kgo/producer.go
index e5d382e7..7a47fb91 100644
--- a/pkg/kgo/producer.go
+++ b/pkg/kgo/producer.go
@@ -576,7 +576,7 @@ func (cl *Client) doInitProducerID(lastID int64, lastEpoch int16) (*producerID,
 	}
 
 	if err = kerr.ErrorForCode(resp.ErrorCode); err != nil {
-		if kerr.IsRetriable(err) { // TODO handle ConcurrentTransactions collision?
+		if kerr.IsRetriable(err) { // this could return ConcurrentTransactions, but this is rare; ignore until a user report
 			cl.cfg.logger.Log(LogLevelInfo, "producer id initialization resulted in retriable error, discarding initialization attempt", "err", err)
 			return &producerID{lastID, lastEpoch, err}, false
 		}
diff --git a/pkg/kgo/txn.go b/pkg/kgo/txn.go
index 164dbe1a..77b9f2b2 100644
--- a/pkg/kgo/txn.go
+++ b/pkg/kgo/txn.go
@@ -608,7 +608,7 @@ func (cl *Client) maybeRecoverProducerID() (necessary, did bool, err error) {
 	}
 
 	kip360 := cl.producer.idVersion >= 3 && (errors.Is(ke, kerr.UnknownProducerID) || errors.Is(ke, kerr.InvalidProducerIDMapping))
-	kip588 := cl.producer.idVersion >= 4 && errors.Is(ke, kerr.InvalidProducerEpoch /* TODO || err == kerr.TransactionTimedOut */)
+	kip588 := cl.producer.idVersion >= 4 && errors.Is(ke, kerr.InvalidProducerEpoch /* || err == kerr.TransactionTimedOut when implemented in Kafka */)
 
 	recoverable := kip360 || kip588
 	if !recoverable {