"Barbaro broke through the starting gate prior to the Preakness, but Bramlage said the injury would not have happened at that time.
"[Jockey Edgar Prado] probably knew, before the horse knew, that something was wrong," Bramlage said.
Prado said he heard the ankle break about 100 yards into the race and he pulled Barbaro up, getting his mount to finally stop just past the finish line less than a quarter of a mile into the race.
"When he went to the gate he was feeling super," Prado said. "I felt like he was in the best condition for this race. He actually tried to buck me off a couple of times. He was feeling that good."
Jockey Alex Solis, who was aboard Brother Derek, said he heard a crack early in the race and saw Prado pull the Dynaformer colt up."
http://www.thoroughbredtimes.com/todaysnews/newsview.asp?recno=63927&subsec=2
I have seen horses break their legs many times.
The gate was not faulty. Horses break through often. Just takes a certain amount of pressure.