Continuity mistake: Kris' blood splatters onto Jesse's left sleeve just before her body drops down from the ceiling. The tiny splatters disappear from the sleeve when Jesse bends down to see if Kris is okay. (00:29:55)
Continuity mistake: The amount of Kris' blood on Jesse's t-shirt changes constantly when he's running from Nancy's house. (00:32:30)
Chosen answer: They were upset because they realise that Freddy is coming to get revenge on them for his death.