When Roy is killed by the firing squad of assassins at 12:47, Pam can be clearly seen.. however in the prior scene she was blown up and Roy said she deserved it. She was already dead.
The caption "Attempt 144 in progress" appears on screen during what is still Attempt 143.
When Roy is shot in the nuts by Pam, the narrator-Roy informs us that was attempt number 15. But earlier in the movie, Roy tells us that it took at least 22 attempts to get that far in his journey.
When Roy comes out of the bar's restroom after searching himself, and stops to speak with the security expert, Michelle Yeoh is visible at the table behind them. Earlier, Roy had stated that if he did not get to it first, she would take the last seat at the bar.
At 5:12 Roy crashes into the side of the mini van, leaving dents in right side of mini van and left side of charger, at 5:31 both cars take right hand turn and dents are gone in both vehicles.
When Kaboom blows up Roy, the former is still so close that he too would have been killed by the explosion.
When Roy is shot through the back by multiple shooters, he has his son Joe in his arms. Undoubtedly some of the those bullets would have gone through his body and into the boy, who instead is unharmed.
When Roy uses the minigun, the shots rip apart the door and kill the assassins behind it. Given the type of weapon, the shots should have passed through the bodies of the assassins. However, not one bullet hole can be seen in the wall a few meters behind the door.
Before Roy's final fight with Guan Yin, after hr wins their training battle he assumes a fencing posture which is not used by practicing sword fighters.
When Roy is gunned down by seven assassins while he sits at the bar, a large blood pool forms on the counter by his right hand. Considering most of the wounds would be toward the centre of his body, one would expect the blood pool would be more toward the centre of his body, nor toward one side. Also, there is no blood spatter near the blood pool or on the counter behind him.
The narrator Roy tells that he knows the name of the sword fighting assassin to be Guan Yin, because she always says "I am Guan Yin, and Guan Yin has done this". But every time she states her name, Roy is already dead with a severed head. There is a common belief that a person is still conscious after decapitation, so it is reasonable to assume this was the intent here.
Throughout the film Roy shoots many people wearing body armor in the chest. In reality, unless very close use high extremely high caliber weapons, these might not be fatal and many would not even pierce the armor.
Many of the people he shoots are simple security guards, and there's no reason for Roy to want them dead. He just needs to get by them. Having them incapacitated, even for just a moment, is really all he needs.
Many of the people he shoots are simple security guards, and there's no reason for Roy to want them dead. He just needs to get by them. Having them incapacitated, even for just a moment, is really all he needs.
On several mornings during the fight in his apartment, Roy throws a mug of apparently hot drink into his assassin's face. Yet Roy couldn't have boiled the kettle, as he's only been out of bed a few seconds, during which time he's been entirely preoccupied with fending off his attacker. However it is clear in the movie that Roy fills his mug from the coffee machine that (probably) automatically brewed before he woke up.
Roy is described as being a Delta Force Captain. Yet 11 minutes in he manages to miss the minivan not once but twice from less than 50 feet. He'd never have made it far in any armed forces missing such a simple (and large) target from so close.
When Roy is ambushed in the noodle restaurant and shot at by the assassins, the toggle on one of the German Twins' Luger pistol goes up and remains fixed in position indicating a malfunction or an empty magazine, but he keeps squeezing the trigger anyway.
When Roy extracts the tracker from his tooth and shows it to Dave, the tracking device has an LED that's flashing. While it is understandable that this might be done to make this plot device clearer to see for the viewers, it is very silly to have a blinking light on an implantable tracker. The light would serve no use, and LED lights consume an awful lot of energy.
At 28:14 when Ventor is talking to Jemma as Mel Gibson is about to lean back in his seat you can see an auto-cue with his next monologue ready to go on the screen.
The very last day when there's no do-over for him (which the movie doesn't show), he still needs to kill dozens of people to save Jemma. Since the day won't repeat, he'd certainly be arrested and go to jail for the rest of his life.