A Time for Celebration?

After the pursuing army is drowned in the sea, the Hebrews begin to rejoice. In The Prince of Egypt, Moses does not immediately join his people in jubilation, but appears troubled at that moment. He has just witnessed the death of many, perhaps including the man he knew as a brother. He turns from the cheering throng and looks across the water. [1:30; one and thirty minutes into the film]

It is almost as if joy is not deemed an appropriate response under the circumstances. The example for this reaction is set by the Lord in a story from the Talmud.