Alex is meeting Gigi for drinks, when he is supposed to be introducing her to Bill. When the waitress brings his drink the glass is nearly full, but when he picks it up to take a first drink, the glass is only half full.
When Gigi and Alex are standing in Gigi's doorway, he is standing in the hall as they speak. One shot she is standing in the doorway, the next shot she is out in the hall as well, next shot she is in the doorway again and so on until the scene is over.
When Ben is teaching Janine the properties of wooden and engineered wood flooring, he's holding a dark brown wood in his left hand and a golden brown panel in his right. In the next shot, he holds up the golden wood in his left hand. In a moment, the panels have switched hands.
When Mary checks her messages, she dials 14103977 but not the entire phone number as shown on the phone screen. Afterwards, the number 14109771308*5585#3 is on the screen showing that she entered her password and started to listen to the messages.
Ben is seen in a convenience store buying beer both in the beginning and in the end of the movie. In the state of Maryland, alcohol can not be sold in convenience stores or grocery stores. It is only sold in liquor stores.