If user a sends user b a subscribe and user b responds with an unsubscribed, effectively denying the request, the server does a roster push to the responding client when user a was never in user b's roster to begin with. The correct behavior is not to do the roster push.
Steps to reproduce:
1. User A subscribes to User B
2. User B denies Subscription Request
3. User B receives a roster item for User A after sending Unsubscribed presence, and user A is henceforth in user B's roster until User B explicitly removes them.