Continuity mistake: Right after Hitch has his bout with food poisoning and he's talking to Sara on the couch, her hair changes. For most of her speech about her sister falling through the ice, the hair on the right side of her face is behind her shoulder. Towards the end of the story it goes in front of her shoulder and then at the end it's back behind it.
Plot hole: In the part where Allegra is speaking to Albert in his office doorway and Hitch slips the pen in his pocket, how did he know she looked away? He's behind a solid door.
Continuity mistake: When Sara arrives at the marina to meet Hitch for their breakfast date, it's supposed to be 7:00 AM. However, the sun is bright & almost directly overheard, as shown by the shadows on their faces, illustrating it was really close to mid-day during filming.
Other mistake: In the scene where Hitch first meets Vance Munson, when Vance is pouring the bottle, the liquid pours and stays level at the same time.
Continuity mistake: When Hitch and Sara kiss the first time, Hitch moves his arm up three different times. Most noticeable in the far away shot.
Revealing mistake: in the scene where Hitch first meets Albert, Albert spills his soda. The can shoots open and spills over the steps. If you look closely the label on the can is upside down. This would be fine if the coke was spilling out of it but it shoots out and when he picks it back up it is still upside down.
Continuity mistake: When Hitch is watching Albert for first time, Albert start to clean the spot of mustard in the scene (we can see him from behind) but it is not until the next shot he takes a piece of paper to clean it.
Other mistake: In the scene at Ellis Island where Sarah is looking at the immigration book with Hitch, the security guard looks straight at the camera for a brief moment.
Continuity mistake: In the scene in Albert's office, immediatly afer he quits his job, his tie keeps swapping from straight to sideways.