When the police bring in Clara Moran (Sherry Conley's sister), Sherry is not wearing any earrings. During her verbal exchange, dangling pearl earrings appear.
Obvious stand ins for the actors in the car going from the prison to the hotel.
When the assassin comes in at the end, he is using a gun, but being a professional, he would not want to make noise like that and risk being killed or captured, so it might be thought he should have used a silent weapon like knife.