The phrase "jumping on the case" typically implies that someone is aggressively pursuing an issue, often with criticism or blame. Antonyms for this phrase may include phrases like ignoring, dismissing, or overlooking. While ignoring an issue may not be desirable, there are times when it may be appropriate to let things go, especially if there are more pressing concerns at hand. Alternatively, a more positive antonym for "jumping on the case" might be collaborating, partnering or cooperating, working together towards a common goal rather than placing blame or pointing fingers.