Continuity mistake: When Milo is driving the car he sees a piece of black pond scum on Nicole's neck. He reaches with his right hand to pick it off while driving with his left hand. After the angle changes he is throwing the scum out of the car with his left hand while his right hand is on the steering wheel, without moving his hands. (01:06:35 - 01:07:10)
Suggested correction: I think he switches when the camera was on Nicole (Jennifer Aniston).
Factual error: Milo gets out of the car to pump gas, but they are in New Jersey where pumping your own gas is illegal.
Continuity mistake: Nicole is sitting in a club with Irene's men at a table. The shot changes from a close up of her and the men, to a close up of Milo (with Nicole and the men in the background). After Nicole is finished talking to Milo on the phone you can see her hang up the phone in the background when the camera is on Milo and then she hangs it up again when the shot goes back to her.
Character mistake: In the scene where Stewart calls Nicole at the end of the movie, he tells her that he got a horse shot in the leg, when in fact they showed him getting the shot in his neck.
Continuity mistake: When Milo and Bobby are eating and drinking in the diner, the level of the Coke in Bobby's bottle, and the level of the beer in Milo's glass differs from shot to shot.
Plot hole: Milo and Nicole go to the club and ask for John. After failing to convince the woman that he works in the senate for Kansas, the woman looks at him and calls him 'Senator' but calls Nicole 'Mrs Boyd'. There was no mention any of their names (even though Milo's surname is Boyd). If the woman calls Nicole Mrs Boyd, she surely must know Milo and that Nicole was his wife.
Suggested correction: The scene starts with the membership director telling them the club is closed for a private event, so we don't see them enter and what they say to her. They obviously cut straight to this part to cut out time. But Milo and Nicole would have given her their names so she could check to see if they're members or on the list.