Popped a spoke on tonight's group ride (rear wheel, the nipple is still intact but I haven't had a chance to inspect the rest of the wheel) - I think I jynxed myself this past Sunday when I was telling someone the Kysrium ES wheel set is bomb proof - 12K miles and both front and back were still true (up until tonight).
Popped the spoke on an uphill sprint, still trying to figure out what went wrong.

The most frustrating part was having one of my stronger rides of the summer when this happened, totally pissed me off when it happened and missed the last 20 miles while I limped back to the shop.
Any ideas what might've gone wrong? (I'm 165 so I don't think weight was the issue).
Any other wheel I'd just pass it off as $hit luck.