Character mistake: There is no way on earth that a police officer would shoot a hostage in the thigh to 'take them out of the equation'. Anyone who suggested such a thing would likely be taken out and shot themselves. Bullet wounds to the thigh are often fatal, as an injury to the femoral artery causes massive and frequently unstoppable blood loss. Breaking the femur often leads to fat embolisms as bone marrow gets into the bloodstream and then to the lungs. In fact a broken femur is a life threatening injury in itself, and a shattered femur - a typical bullet injury - would almost always result in a total amputation. You cannot aim carefully enough to avoid the bone or artery as their position in the body varies, (as will the bullet trajectory upon impact). Jack is an experienced cop and would know the potentially disastrous consequences of shooting someone in the thigh. He'd shoot him in the foot.
Continuity mistake: When the subway carriage bursts out into the street, Annie's handcuffs slide off the broken pole and in slow motion you can see the pole is shorter than all others. Besides, all the other poles in the carriage are intact. (01:49:15)
Continuity mistake: After the bus driver looks at the note "Bomb on Bus" he starts decreasing speed. So Keanu puts the Jaguar beside the bus and tells the bus driver to open the door for him to tell the driver to go at a speed of 50 miles per hour. Just before this you can see a camera shot in which the door is already open. This mistake is easily seen if you watch it in slow motion.
Continuity mistake: When Howard Payne is in the elevator, he hears Jack and Harry doing something from above, and he reaches for his bomb trigger. In slow motion when he's picking it up, it has two buttons on it, yet when Howard pushes one of the buttons, the device now has three. (00:13:00)The-Immortal
Plot hole: It is never definitively stated if the bomb is tied directly to the axle, triggered by the speedometer instrumentation or throttle. Regardless, as long as the wheels keep spinning above 50mph the bomb will not explode by design. This means that if you lifted the wheels of the bus off the ground or you bottom out, you could keep accelerating without any speed at all. This could be accomplished in any number of ways. One example would be driving on grass and keeping the tires spinning.StevensPointWI
Plot hole: Payne's finger prints would've been all over the elevator, on his shotgun, and near the area where he killed the security guard as he was never shown wearing gloves. Since he was a former police officer, I would assume his prints would've been on file with the FBI and in a multitude of databases. You would think they would've been able to identify him much earlier in the movie than they did by running the prints through all databases of finger prints.
Plot hole: The police thought they could catch the bomber at the ransom drop because he did not know that the bus had exploded. However, the exploding bus would have created a huge plume of smoke that would have been reported by the media. (01:30:00)subspace