Full disclosure: I don't play pick-5's. They are beyond my ability and bankroll.

My guess, however, is that they don't know who the post-time favorite will be when they post the will-pays, so they don't count tickets with scratched horses (11/14/15/16) as winners. Under my theory, you would have gotten the full $1,120.80 (for $1) if the someone other than the 9 (maybe the 4) had been the post-time favorite. Since the 9 was the post-time favorite, the will-pays on the other horses should have been accurate.

My theory would also explain why the pick-4 will-pays were inaccurate, but is blown out of the water if the pick-3 will-pays were wrong. According to the chart, the pick-3 paid off only to the 9, not to the scratched horses.

Edit: I now see there was a consolation payoff to the pick-3 due to a late scratch in the middle leg. I don't know how that figures into the will-pays.