UPDATE:
Response by CA in regards to the award booking.
"The mileage award seats allocated for the CA flights in question were limited and were used as follows: 2 seats were used by CX, 2 seats were used by AC, 1 seat was used by US Airways and 4 seats were used by UA. None of these seats were allocated or given to CA customers. When an airline such as UA cancels its allocated and reserved mileage award seats, CA cannot allocate more mileage award seats for use by UA ticketed passengers after CA cancels its reserved mileage award seats, as this would open the door to a carrier such as UA controlling the restricted inventory of CA seats to be used by UA mileage award passengers."
So the award theory, that CA passengers took the extra award seats, seems wrong. Revenue seats were probably still available (and not affected by award seats?).
I can guess that MAYBE someone on UA canceled and rebooked other UA awards. Seems mighty fishy, and seems that UA may should have a good record on this, if it was rebooked UA.
Thoughts? I am as puzzled as ever!