What's a bit odd to me is that Pyro's trainer, Steve Asmussen, chose to put and keep Shaun Bridgmohan on the horse rather than the far more capable Robby Albarado who rode Curlin, last year's Horse of the Year, for him.
It would be rather silly to take Bridgmohan off since he's been on Pyro since his maiden race and has done quite well with him. It's also possible that Albarado had already committed to another horse who didn't quite make it to the "first Saturday in May" and was subsequently left with Z Fortune. Both jocks are quite capable imho. If I had my choice of any jockey it would be Cornelio Velasquez who lost out when War Pass was injured.