So why didn't he go for it in the short? If he can do it?
I can only speculate, of course, but putting an iffy element in the SP is much more of a risk than putting it in the LP. All three jumping passes are required elements, unlike the LP, and also unlike the LP there's really no opportunity to make up points after a mistake. Jason needed to set himself up in the top group in the short, which is what he did, and the way he knew he could do that was with a clean skate. No doubt his goal was to make sure he's chosen for the world team. This makes perfect sense to me. If this was a random grand prix, I'd say take the risk in the SP, too, to get the quad out there as much as possible. But the strategy with the world team on the line would be different here.