Janine is introduced filing her red fingernails. But her nails aren't painted red any longer when she hangs up the phone after the first call. Her nail polish remains missing during the second phone call as well.
When the Ghostbusters enter the bedroom and the door closes itself behind them, Ray's hair changes from his usual color to the darker shade associated with Peter.
As Ray drives back to Mrs. Rogers house, he isn't wearing a proton pack. But on arrival he jumps out of the car wearing one.