Fix potential nil panics

op-batcher/batcher/channel_manager.go

@@ -82,7 +82,7 @@ func (s *channelManager) TxFailed(id txID) {
 	}
 
 	s.metr.RecordBatchTxFailed()
-	if s.closed && len(s.confirmedTransactions) == 0 && len(s.pendingTransactions) == 0 {
+	if s.closed && len(s.confirmedTransactions) == 0 && len(s.pendingTransactions) == 0 && s.pendingChannel != nil {
 		s.log.Info("Channel has no submitted transactions, clearing for shutdown", "chID", s.pendingChannel.ID())
 		s.clearPendingChannel()
 	}

op-batcher/batcher/driver.go

@@ -212,6 +212,7 @@ func (l *BatchSubmitter) loadBlocksIntoState(ctx context.Context) {
 		latestBlock = block
 	}
 
+	if latestBlock != nil {
 		l2ref, err := derive.L2BlockToBlockRef(latestBlock, &l.Rollup.Genesis)
 		if err != nil {
 			l.log.Warn("Invalid L2 block loaded into state", "err", err)
@@ -219,6 +220,7 @@ func (l *BatchSubmitter) loadBlocksIntoState(ctx context.Context) {
 		}
 
 		l.metr.RecordL2BlocksLoaded(l2ref)
+	}
 }
 
 // loadBlockIntoState fetches & stores a single block into `state`. It returns the block it loaded.