If a horse is scratched behind the barriers BF often don't remove it from the betting. After the race the usual deductions are made. However, here's the quirky bit. If you bet in running you get the prices shown on the screen (with the scratching still there) and no deduction is made after the race.. If it is a shortie that was scratched you are getting inflated odds about whatever you back in running but you are getting diddled if you lay in running on one of these races.

Caveat aleo.