I don't have the pattern, but when I did a little search, I did see lots of pictures of it. It appears to be a popular pattern, and there have been several Knit-Alongs on it.
The center of the back looks like the tree, which, of course is more than 8 stitches.
Can you elaborate a bit on your problem?
It could be that the bobbles 'add' stitches, but since they're all done in one stitch and then get reduced back to one again, they don't take up any more space on the chart. Just a possibility.