(at around 58 mins) When Mullins takes Ashburn to her parents house. The family is arguing at the table and her brother enters the front door carrying a bag of shopping. The bag starts off with nothing in the top, then bread appears, then it disappears again.
During the opening chase, Mullins makes a sharp right and the hubcap comes off the left front wheel. When she is pulling up to huge police station, the hubcap is back on.
When Mullins throws a watermelon a Rojas it rolls away from him but in the next shot where she goes to cuff him it is much more broken and a piece of it is on the other side of Rojas, and when it cuts back to the side view it's mostly intact again.
On the sidewalk in which Mullens runs into an old one-night stand, there is an African American man wearing a blue shirt that walks by them repeatedly from behind.
When Ashburn and Mullins are in the bathroom fixing Ashburn's "look", after her pants have been cut, her shirt changes from being tucked to un-tucked (in the mirror) repeatedly.
When Ashburn is dragging herself along the floor in the hospital, her leg leaves no trail of blood in spite of being stabbed twice.
During the club scenes, Ashburn and Mullins go to the restroom. Too much times passes for no one to enter the restrooms, considering the length of time the two characters are inside.
Levy tells Ashburn to go to the Boston Police's East Boston precinct, which is identified as G-5 in Area F; in reality it's A-7 in Area A. Also, a Boston Police district's identifier shares the same letter as the area it's in, so it should have been identified as either F-5 or located in Area G.
When Mullins bursts into Jason's room at the end you can see behind the door there is nothing and no one. It flashes to Jason laying in the hospital bed then back to Mullins. As it does this it is clear the little door behind the room door does not appear to open, yet Larkin appears from behind it.
After the car explosion, the fire engine in the street is not running it's red lights. Anytime a fire apparatus is parked at a scene it must keep its warning lights on.
When Special Agent Ashburn locks her Chevrolet Impala, it beeps. General Motors cars sound the horn when the door is locked.
When Ashburn is leaving NYC to head to Boston, she's seen driving East on the 59th St Bridge, which would take her to Queens - and then onto Long Island. To drive north towards Boston, she should've been shown on one of the bridges to the Bronx.
When Larkin reveals himself, Mullins is openly moving her hands around and even tries to untie her partner, in plain view of Larkin. He somehow doesn't seem to notice this; and when Julian comes back Mullins goes back to pretending to be tied up.
At the end of the movie when Ashburn and Mullins arrive at the hospital to save Mullins brother, Ashburn is left in the foyer as Mullins races to the ward the brother was in. Part way to the ward, Mullins finds out the brother has been moved to another ward. However Ashburn goes directly to the "new" room even though she wasn't present when the doctor informed Mullin.
Rojas says that Tatiana has brown eyes, but they are clearly blue.
Rojas (Spoken Reasons) talks about doing 'sodukas'. When Mullins (Melissa McCarthy) corrects him on his pronunciation, she also pronounces it wrong as 'suduko', instead of 'sudoku'.
When Mullins is reading the teachers' quotes from Ashburn's yearbook she says that one of the teachers put, "Have a great summer," but later when Ashburn is reading her yearbook it clearly says, "See you next year."
If Craig was a true albino, he would have pink eyes - NO pigment.
Although Mullins's family are Bostonian to the extreme, Mullins seems not to have any trace of a Bostonian accent.