Toward the beginning of Finding Dory, Dory acts as an assistant to Mr. Ray to help teach the children about migration. Later in this scene, Dory has an accident which renders her briefly unconscious. When one child asks if Dory is dead, Mr. Ray informs him that she is alive and the children appear to groan in disappointment.
Is there anything in the movie that would suggest why the children would be disappointed to discover that Dory is not dead? Sure, Dory's short-term memory loss can be an annoyance at times, but the children (especially Nemo) appear to have a good relationship with her so it seems odd to me that the children would be noticeably disappointed to find that she was not killed.