For a class of delay-tolerant networks, it is assumed that the future topology changes are predictable and therefore, it is possible to find paths for data bundles by traversing the contact graph. This is the method used by Schedule-Aware Bundle Routing through Contact Graph Routing and the reward shaping method proposed for the Cognitive Space Gateway (CSG). In this work, the performance impact of anticipated contacts that randomly fail to occur is investigated. A queuing model is first formulated to gain insight into the end-to-end bundle delivery performance drop compared to the optimal performance. Then, experimental results provide further indication of the performance impact using an emulated space DTN environment. While a contact miss event can be hard to predict or to avoid, bundle re-routing is investigated for CSG routing as a possible mitigation method and is experimentally tested.