I’ve a vague memory of one about 4-5 years ago…someone I know backed it at 7/2 I think and it won at 25’s and he wasn’t on b.o.g either! Something in the back of my mind saying it was trained by Brian Ellison…could be wrong though?
Too long ago for me to verify any details but remember a horse called Stanstead or Stansted drifting from warm favoritism to 25-1 in quick time and winning.