When the travel agent call Carol's bank, the agent is provided the exact account balance (as well as recent transaction history). Banks can only verify if a certain amount is in the account to cover the funds (whether it's a "good" check or not at that time). This would be a severe breach of customer privacy.
When Alice opens the Brady's front door, the dead bolt is in the lock position, but still opens without her unlocking it first.
Mr Prescott has a sales tag still attached to the sleeve of his robe.
In the Christmas tree decorating scene, Greg talks to Peter about his stuffed clown and how he'll burn it this year if he finds it. In the next scene, when Bobby is talking to Alice and Carol, you can hear the same script being used as background noise and chatter once Alice starts to cry.