When Gwen is leaving Charlie's house when he almost kisses her, she gets in the car but in the next shot, her head can be seen in the lower right corner of the screen.
When Gwen presents Charlie with the new cufflinks he requested, he removes the cufflink he is wearing from his right cuff; in the next shot, Gwen removes the same cufflink that Charlie has just removed and installs the new one.
When Charlie and Victoria have a video conference, there is one shot in which Charlie has no suit jacket on and another shot Charlie has on a suit jacket.
When Gwen goes in to decorate the office she only has one box. The decorations she used when finished would take several boxes to carry them in.
When Owen presents Gwen with the Christmas card he has made for her, she says it's the greatest & thank you, as she opens her arms to offer him a hug; Owen hugs her right cheek to right cheek but in the immediate shot angle change, they are hugging Heart-to-Heart or left cheek to left cheek.
When Charlie Owen & Gwen are viewed from behind while looking out the window as it begins to snow, Gwen is holding her Christmas gift in her right hand; it can be seen immediately behind Owen's back. In the next shot angle change, when the three are front-facing, viewed from outside the window, she is holding her gift in her left hand in front of Owen.
Gwen tells Charlie that he has gained weight because, when he tries on the suit jacket she brought, it is too tight. He had not let her measure him, saying his tailor had his measurements. That he is surprised at the non-fit is implausible because his existing suits are presumably the same size and would therefore also be tight.