Jumped on one's case is an idiom that means to criticize, scold, or harass someone. The antonyms for this expression could be praised, complimented, or encouraged. Praised means to express approval or admiration for someone's actions or behavior. Complimented means to express appreciation for someone's characteristics. Encouraged means to give confidence, help or support. It is always better to use positive language and avoid negative expressions as it creates a better environment and does not harm anyone's feelings. Therefore, instead of jumping on someone's case, we should try to praise, compliment, or encourage them.