It's not logic, you're giving me way too much credit. It's just how they normally behave, shorts don't freak out because they're only up $12 a share rather than $13. They don't get a margin call in that situation. I've never seen shorts panic far in the money. I've never even heard anyone tell a story that goes like that.
Intelligent shorts, who dumped close to the IPO price, are still feeling like geniuses. Like I would feel if I'd listened to my mother-in-law and bought Apple at $250. Too bad it's $450 instead of $700, but panic? No.