When you give a guy a raise, thats the time to increase his responsibilities. Reward him at the same time you motivate him to do even more. Hit him with more while hes up, and never be tough on him when hes down.
When hes upset over his own failure, you run the risk of hurting him badly and taking away his incentive to improve. As a mentor used to say, “If you want to give a man credit, put it in writing. If you want to give him hell, do it on the phone.