A Breeders' Cup-commissioned evaluation of the catastrophic injury that led to the euthanization of Mongolian Groom (Hightail) in the GI Classic has concluded that the gelding had small, pre-existing stress fractures in both hind cannon bones, and that when the one in his left hind displaced during the race, it created chain-reaction downward force that acted "as a screwdriver" to apply "a huge amount of torque to the bone," causing multiple fractures in that leg. The 25-page report, released Wednesday by the Breeders' Cup and authored by internationally recognized equine orthopedic...