When Arthur saves Gwen's drawing from the fire the top left corner is burnt away. When he reaches Trelew he looks at the drawing and it is whole again.
When the seal enters Santa's North Pole Control Center a bird flies overhead and poops on Steve. The continuation of that scene shows no poop on his suit, and then it reappears a short while later.
Scandinavia celebrates Christmas on the eve of the 24th. So even though Denmark is apparently Santa's first stop on Christmas night, the children would have long since unwrapped their presents when he got there.
Steve's tablet states that he has completed Hungary. However, according to Hungarian tradition, Santa visits Hungarian children in the night of 5 December, and Little Jesus brings gifts to them already in the evening of Christmas Eve.
Sunrise in Trelew on 25 December is 08:18 not 07:39.
Arthur falls out of the sleigh as it flies over Cuba. Several seconds later, the gift-wrapped bike falls out, landing directly in front of him. Given the speed at which the sleigh was flying, the bike should have landed much further away.
After it is discovered that Santa has missed a present when he's returned home then the time would already be well into the afternoon on Christmas Day in England so Gwen would already be aware that she wouldn't have the present from Santa before they try and deliver it.
Grandsanta says that he is 136 years old. But if he were 136 years old, he would not have been able to be Santa for 70 Christmases and then see his son, the current Santa, complete 70 Christmases as Santa. However, as mentioned in the beginning of the story, the portrait for Santa Claus the Nineteenth(Grandsanta) completed only 39 missions from 1902-1941, making him 27 years old on his first mission.
When Arthur jumps out of the sleigh into Trelew, England to get to Gwen's house in time, he uses Santa's toy sack as a parachute. He has the bike grasped to his body but when the toy bag turns upside down as he's floating to the ground, a toy falls out, which could imply that they missed not just 1 present but 2, and that they didn't just miss Gwen. However, these sacks are not used on the S-1, and it is more likely that the toy was left over from the last time the original sleigh was flown, presumably decades ago.
Gwen's address is number 23, but she says there are only 9 houses in her road. This isn't an error, as a complex of houses covers multiple roads.
The word TOYS on the toy sack Arthur uses as a parachute should be upside-down, as the sack was turned upside down so it could be used to get Arthur to the ground.
After the plane destroys EVIE, the S-1 soon appears with Malcolm, Margaret and Steve. However, it is impossible that the plane didn't notice the S-1 appearing close to it, as the S-1 is shown to be visible from above. If the UNFITA can detect electronic devices, such as the slippers, they also should have noticed the S-1, which has a technology "more developed than Pentagon's".
The movie opens in "Aarhus, Eastern Denmark". Aarhus is actually the capital of the westernmost part of Denmark, Jutland (though it's on the east coast of Jutland, which is probably what confused the script writers).
Also, Aarhus has very few buildings with more than five floors like those seen in the movie.
There is no city or town named Trelew in Mexico. But there's one in Argentina.
After Arthur hooks on to the upside-down turned sleigh, it takes him over a minute to get it under control and make a U-turn, but less than 15 seconds to make it come to a full stop. Thus it couldn't possibly have returned to where the boat was, and crash on top of it.
Ms. Claus states that Trelew, Cornwall is on a course of 187.7 degrees from the North Pole. However, everywhere on the planet is due south from the North Pole. That would be course 180.
Even though Gwen only asked for one gift which was the bike and seeing how Gwen is an only child, there appears to be tonnes of Christmas presents under the tree, and surely her Parents couldn't have asked for that much.
When the elves are panicking about the Activity Farm in the boy's bedroom, one of them remarks that Santa will wake him, when the boy was already awake.
Arthur's slipper should have been thrown out of the sleigh when the drone first appeared, to break the targeting lock.
Bryony claims that she wrapped 264,000 presents in three days. Even working non stop, this would be just over one every second, which isn't possible.
Just after De Silva is told the sleigh has just gone into orbit, the scene shifts to Arthur in the boat preparing to catch the sleigh, which at this point is still circling the world within the atmosphere.