During her video chat with Howard from earth, Bernadette can be seen wearing the "Star" necklace Howard had promised to take with him into space in the previous episode.
In Howard and Bernadette's "space call", Bernadette is wearing the Star necklace given to her by Howard in the previous episode. Which is odd since It should be in space with Howard as that was his promise to her.
When Raj calls for the waiter to bring champagne, the waiter is standing right behind him and starts to walk away. In the next shot the waiter is standing still in a different place, and later walks away from his original starting point.
When Amy leaves the table in disgust, she sets down her glass. In the next shot it's not where she set it down, and continues to move around throughout the scene. Also, her napkin goes from rumpled to flat and back.
When Raj sits on the couch drinking with Leonard and Penny, a wrinkle suddenly appears in the tablecloth, then disappears.
In one scene where Howard is talking to his mother from the ISS, a yellow hard-shell suitcase can be seen strapped to the wall behind him. Such a suitcase would not be on the space station as any luggage would be carried in lighter, more easily stored cases or bags.
Near the end of the episode, Raj refers to his dog as "he". His dog is named Cinnamon and has always been referred to as a female.
It is a bit weird to hear Howard's mother call Bernadette "the little Polish girl", seeing as her own last name Wolowitz is just as Polish as Bernadette's name Rostenkowski. So she is either a Polish American herself or she once married a Polish American (or both).