Huh. Maybe this relates to what happened to me in Venice.

Booked a five night stay with points. They agreed to one night reimbursement as a service recovery (see Hilton Molino Stucky thread). This was reconfirmed at checkout. When that appeared (+70K points), there was also an entry for "late cancel" (+280K points). I couldn't tell if this was a decision made after the fact as a service recovery, or some kind of error.