This time I got to see it for myself. I reversed a WO transaction for 5 each of item 70-FA-RD-01 by opening WO-I, looking up the WO #, selecting and answering Yes to back out the transaction after tabbing from the date field. The result was that a blank location was created in BKICLOC with just the item code and a UOH of -5.  
 
The item has lot control turned on.
 
We are on the latest update and SP4.