On the occasion that a counter wound rib is called for (for the reason Hans already stated) I usually counter wind the body material and then wind the rib in the usual direction. Probably because the first time I counter wound the rib it came loose on the first fish. The rib is only held with a couple of turns of thread, whereas the body material is tied down with twice the number of turns of thread (the ones tying off the body material, and the ones tying off the rib), and by the rib itself. Where I differ is to tie in both body and rib material at the tail and wind toward the eye.
Cheers,
A.