ORLANDO, Fla. — One bad club choice and swing by Billy Horschel turned a special day into a two-hour scramble to salvage his second round at the Arnold Palmer Invitational. Cruising along at 4-under par through 7 holes on the back nine, Horschel arrived at the daunting par-3 17th measuring a stout 238 yards Friday. Following a lengthy discussion with caddie Mark Fulcher, Horschel hit a hard 4-iron. “Afterwards, I thought, man, maybe I should have hit a high, soft 3,” Horschel said. “We have said we’re agreed to disagree.” Horschel’s miscue led to a double-bogey 5. The 37-year-old’s rhythm soon…