Sales Order line 980-999 but no entry in sales ledger

Is there any reason (outside of an SQL update to the data) why we would ever see a sales order line cancelled 980-999 but no entry in the sales ledger and no cancel date? It seems like some changes on the shipment side can update the sales order line, but I would assume it's always going to update the sales ledger. Can anyone confirm that?  Any other thoughts?

Update:  these can be demand-generated orders also.  But again, I would assume that a line cancelled through demand would create the appropriate ledger records...