Corrected entry: Mr Big said he would leave for California at 5 pm. Carrie runs into Samantha at the hospital just after Samantha spied on her lover during lunch. After that, Carrie immediately leaves the hospital to see Mr. Big but he's gone already. That would be a VERY long lunch Samantha had.
Corrected entry: In Episode 66 "I heart ny", Miranda gives Carrie a cell phone in order to have her on call when she goes to the hospital to deliver her baby. When the phone rings, Carrie tells Big that she never had one and does not know how to use it. However, in Episode 20 "The man, the myth, the viagra", she receives a call from Miranda and whips out her cell phone from her purse to receive it.