Its definitely all composite, i noticed the same kind of thing on a 7k i think just last week when i was helping an equipment manager sort through a pile of broken sticks to send back. Reebok makes those sticks in a ton of different ways... for example: some of the 10ks will be painted black at the shaft and some wont have paint and you can see the carbon weave, and even though thats just a cosmetic difference, they also have a completely different feel even if they are the same flex. also once and a while i come across the ones like you have too.