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: When Geoff meets Hitch in the zoo, he says he got his number from Albert Brennaman, but we have not seen a connection between Albert and Vance, so there is no reason for the team to tie it back to Albert and Hitch. Even if the tickets for the club being in Alex's name for Albert and Allegra's date were a clue, then Sara would not have been surprised to see Hitch at the zoo... So how did they know to use Albert's name? Why wouldn't they just use Vance's name, since they actually got the connect from him, believing that it was in fact Hitch's job to hook men up with women? (01:21:30)
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.