Originally Posted by Bagels
Most likely this involved a partner airline (other than KL).
When booking an award involving another airline besides NW/KL, that airline has up to 24 hours to confirm the reservation. While they usually will, they don't always do so.
It's indifferent from buying a revenue ticket. Say you buy a ticket EWR-HKG/CO-MNL/CX, CX would have up to 24 hours to confirm the reservation. If they don't, your ticket would be cancelled -- even though you purchased it.
While your points are valid, the handling of the situation is the issue here. If it's simply one partner segment that failed to confirm, usually a return call is in order, or if the customer calls back in, the remainder of the reservation would still be in tact, and they would only have to find a workaround for the affected portion.
On another note, purchased award reservations issued by NW are more susceptible to cancellation than those issued by other carriers because of NW's practice of delaying ticketing. Other carriers can audit award holds to ensure the space will be used, and excessive holds that are not ticketed can be cancelled if they're not ticketed. So, while you think you have "purchased" a NW reservation, NW does not immediately ticket, so if the ticket isn't issued, a partner may simply see that as a hold. If NW sits on that for days or weeks, the partner may see that reservation as an excessive hold, which makes that space subject to cancellation.