There's another factor at play, too. The main warehouse may have product sequestered for the sale that has not yet been delivered to a retail location.
As it's been explained to me, when wine is received at a store, the quantity is then activated in the LCBO inventory system. So, store X might have a 1-case allocation but is showing quantity 0 now. When store X gets those bottles this Thurs or Fri, then that quantity would be updated to show 12. So, really, you have to check Friday evening to know what store has what physical quantity of a wine.