Urine testing of Kentucky Derby winner Medina Spirit has shown that a steroid present in the colt’s system came from a topical ointment and not an injection, according to an attorney for trainer Bob Baffert. Medina Spirit tested positive for the steroid betamethasone after winning the May 1 race and is facing disqualification. Baffert had said an ointment used to treat the colt for a skin condition daily up until the Derby included the substance. Betamethasone is a legal substance, but it is not allowed on race day in Kentucky, Maryland, and New York, home to the Triple Crown series. Craig Robertson, Baffert’s attorney, said late Friday that testing of the split sample was completed by a lab in New York. “It has now been scientifically proven that what Bob Baffert said from the beginning was true—Medina Spirit was never injected with betamethasone and the findings following the Kentucky Derby …