Hey BC....did a Bing search and read through four or five of them. Doesn't seem like it will be a problem unless it is severe. Here's the link for your review.
Since the pup is only 7 months old it might be difficult to tell now how it will be when full grown. At this age then often look all out of whack physically. Hopefully when he matures what you are seeing now will go away. Have you visited with your vet? If you and the vet do feel it is a defect I would be in touch with the breeder.
My current 6 year old EP is a big dog at around 68 lbs and he has a bit of cow hock. I always think about it as he canters off. But when he opens the throttle, he looks graceful as they get.