When Tim is moving in he picks up two boxes from the back of his truck. When he walks in the front door he only has one.
When Jamie and Lisa are firing the gun, it never recoils, evidencing that blank rounds were being used.
Jamie is wearing the same outfit when she meets Tim and again when she meets Lisa days later.
Unless it was the doctor's first day also, he would have recognized Jamie as a patient and she would not have been able to leave.