When Max gets blown away, we see Ryan in the abandoned building and the blast knocks out all the glass of the window but when the smoke clears the glass remains.
When Ryan Gaerity is drinking with Max, he drinks almost half the beer served, but when he picks the glass for another sip, it's almost full again.
When the bomb truck is "blown away" Jimmy, who is in close proximity to the explosion, falls toward the explosion. This action goes against the laws of physics seeing as the explosion flipped the truck onto its roof.
When disarming the device on Anthony's head and the second device in the speaker, Bama is told he doesn't need to be there. As he gets up you can hear and see Bama drop the side cutters onto the shelf, but when he leaves you see him pass them to Jimmy.
Position of Kate's Jeep at the beach house. Early on, we see her Jeep facing the water with the driver's side door closest to the beach house. Later, when Gaerity secures the latch on the hood, we see that the Jeep is facing away from the water and the driver's side is away from the beach house.
There is a clip of a Red Sox game on the TV. When Mo Vaughn hits the homerun, the announcer says it's "over the green monster". The green monster is the name for the left field wall. Vaughn clearly hit it over the right-center field wall, nowhere near the green monster.
During Blanket's funeral, Lt. Dove is wearing a star on his shoulder and Capt. Rourke is wearing two stars. In the Boston PD, there are not 1 or 2 star ranks. A lieutenant is a single gold bar and a captain is two gold bars.
The old ship is from "La Cieba, Honduras." It's correctly spelled "La Ceiba."
The Guinness in McDowell's Pub has no head. A thick creamy head is a distinctive characteristic of Guinness. No "Irish" barman would serve Guinness in such a manner, nor would any true Irishman drink it. The Guinness was also served in the wrong glass.
In the bombing scene at MIT, there are no Cambridge Police or MIT Police present. MIT is in Cambridge and that city's police would be the first called to the scene, not the Boston Police Department.
In one of the shots of the Boston Pops playing the 1812 Overture you can see very clearly Pops conductor and Star Wars composer John Williams conducting the orchestra, then when the music ends the conductor is his successor Keith Lockhart.
In the hot tub, while Katie is dunking Jimmy in the water to sober him up, we hear Jimmy start talking to Katie while his head is still under water.
Jimmy discharges his pistol in the hot-tub when Kate shows up and the slide retracts to the empty position. Later in the scene when the pistol is sitting on the edge, the slide has retracted to a ready position. When Kate leaves to prepare for the concert, the slide has retracted to the empty position again.
When Blanket is thrown back by the force of the bomb exploding, the cable pulling him is visible.
A launching board is clearly visible throwing one of the actors into the air to simulate the impact of an explosion in one of the Ireland flashback scenes.
At the beginning of the movie during the disarming of the bomb at MIT you had Dove and Cortez in the room with Nancy and one or more bomb squad personnel in the hallway. The bomb squad personnel all had to be there; Nancy did not. Why didn't Cortez or one of the other bomb squad personnel take over the keyboard from Nancy so that they could get her out of there? This just did not make sense.
When Gaerity orders Guinness in the Irish bar, what he is served is more like lager (totally wrong color and consistency) yet this doesn't seem to faze him.
At the end Jeff Bridges' jeep hits a wall. An extra gets clipped and attempts to limp away.
After the bomb squad lorry is blown up, a mobile phone lying on the floor rings and connects without anybody being near it and 'accepting' the call.
Cell phone has a ring tone when picked up at 52:24.
When Max is fishing by the dock, as he is reeling in a fish he talks to himself, but his mouth doesn't move.
In the first shot of the Boston Pops Orchestra (98m) we hear the 1812 Overture, but the conductor is conducting a completely different piece, at a different tempo and in a different metre.
Visible reflected in a mirrored building as the helicopter lands at Copley Plaza.
The reflection of the camera crew is visible on Gaerity's sunglasses as he talks to Lizzy on the beach.
In the scene in which the bomb squad truck blows up, the cable that is used to flip the truck can be seen attached to and then releasing from the roof of the truck.
When Forest Whitaker's character Anthony Franklin is jogging outside, he runs up a flight of stairs and stops right in front of the camera. The piece of tape marking the spot at which he is supposed to stop is clearly visible.
The final car crash scene occurs near Boston Common on the corner of Joy and Beacon Street, as the car comes out of Joy onto Beacon. While it appears that much of the footage was filmed on Joy or adjacent streets, it could not have happened the way it did in the movie. Joy Street is only about a quarter mile long, and all but the final half block (shown correctly in the movie) is uphill when going toward Boston Common. This would obviously ruin the plot line that they couldn't apply the car's brakes. The stunt sequence when Jimmy jumps to the jeep from the motorcycle was shot going down Anderson St. on the other side of Beacon Hill (northbound) where it crosses Phillips. (A lot of movie lights are visible in the open, though.)