Fault injection is widely used for validating dependability of computer systems. These techniques have been traditionally used for testing dependability of the both hardware and software systems. With widespread use of model based development in automotive software development more sophisticated needs arise for using fault injection techniques at the model level, which can yield significant benefits in combination with model-based testing or model mutation. In this paper, we address challenges with injecting faults into behavioral models in terms of analysis of results and propose a framework for distinguishing between correct and incorrect simulation results. The focus is laid on an important challenge encountered when injecting faults in continuous models - managing system- environment interdependencies. We analyze the problem in details and outline an effective approach to deal with this problem.