The Man from Toronto uses 19th century American poetry as code words. When he challenges Teddy Jackson's claim to be the assassin, he tells him to prove it by reciting some Keats. Keats was an ENGLISH (not American) poet.
About 1 hour into the film, Harrelson hands Hart a passport saying,"You're gonna need it." But you do NOT need a passport to fly from PR to the USA.
Shoot out with The Man From Tacoma at about 01:29:46 into the film involves a McLaren 12C which is made of carbon fiber. However, bullet holes appear to be in metal body.
At 14:18, Kevin Hart is clearly pretending to turn the steering wheel as his hand is moving in a circular motion but the wheel stays still.
Towards the end of the film when Teddy runs out of his house on the way to the station to meet his wife, he runs past the same blue Mazda 3 which was blown up at the cabin in the woods.
Hotmail performs a password quality check. It may have been possible in the earliest days of Hotmail (year 1996), but today a password "PASSWORD" cannot be set.
During the fight scene at about 1:33h, a bad guy is hunting "the man from Toronto" up some stairs. The Bad guy is swinging a hatchet from side to side, and besides some pictures, he hits the walls twice. But as the camera follows, about six impact marks from the hatchet are clearly visible. Assumably from earlier shots.
When The Man From Toronto is having a flashback to his first hit, he is holding a suppressed .45 pistol, aimed at his target and ready to fire. In fact the hammer is down and not cocked and the gun would not fire in this condition. To fire, a .45 caliber colt style pistol has to be cocked back in order to fire.
Hotmail takes measures against brute-force attacks such as rate limiting after too many failed authentication attempts in a row. A statement "we have mail account's password in two hours tops" does not take into account of this. (NB: Hotmail has a maximum password length so you can state an upper limit.)
When Teddy and the Man from Toronto land in Puerto Rico, then walk over the edge of a cliff and see San Juan. However, San Juan is on a coastal plan and the only elevations in Puerto Rico are the interior mountains.
Washington DC has had a building moratorium in place for nearly 100 years that you cannot build any building in the District higher that the Capitol, which was set at 12 floors. At 29:19 as Kevin Hart emerges from the FBI car, you an see a 30 story building in the background. Then he heads to the fictitious "WASHINGTON ART GALLERY", which in reality is called "The National Gallery of Art"
Yorktown, Virginia is a sleepy, small town, population of around 300 people. It has almost none of the features depicted in the movie on the way to the train station.