Sadly there have been some otherwise good reviews/videos of this gun on the internet that do not stress the necessity of locking the bolt back before taking the gun down. The extractor takes the hit if you don't. Luckily it's an inexpensive part even if you break one.
I'd send it back to Ruger they'll probably give you a new one, and then also, buy yourself a Volquartsen extractor, which is a nicer and tougher piece and isn't a lot of money.
http://www.midwayusa.com/product/363360/volquartsen-exact-edge-extractor-ruger-10-22-10-22-magnum-mark-ii-mark-iii-22-45
I've got one coming to me next week, and I'm going to slip it into the pack as insurance. Everyone makes mistakes from time to time.