Factual error: Though the movie is playing with historical events for "laughs," it should at least be pointed out for the record that Queen Victoria died in 1901, and the Titanic didn't launch until 1912 (and its construction didn't even start until 1909). So, obviously, there's no way Victoria could have toured it before its maiden voyage. (And the movie acknowledges that it's supposed to be THE Titanic since it shows Moriarty reading a newspaper reporting that it sank, to say nothing of the Billy Zane cameo).
Factual error: Max could not have been accidentally shot when Annie drops the revolver. She dropped it when she was startled by firing it into the ceiling so the hammer would still be sitting on the spent/empty shell casing. The trigger or hammer must be pulled back in order for the cylinder of a revolver to rotate to the next live chamber.
Factual error: The plane used in the film to take Juliet back to London towards the end of the film is a replica of a Dakota C-47. She is painted with black and white "invasion stripes" on both the upper and lower surfaces of the wings - approved in May these were only widely put into use for D-Day in June 1944. After one month the upper surface stripes were ordered removed, and by the end of 1944 they were ordered completely removed. By 1946 when the film is set they would have been long gone from any serving aircraft still flying.
Factual error: In the police shoot out scene, you can see that the plate carriers the actors are wearing are really empty. Brolin sticks his hand into Forsing's vest after he was shot, the vest easily folds away. You can also see in various shots how theirs vest bend with their bodies, in a way they wouldn't if they had plating in as they should to protect from bullets.
Factual error: When Mary and the children go to the bank the long shot of the bank shows a statue that was not erected until 1994.
Factual error: The opening scene shows Cassie and Bryan booking their holiday on a laptop. The dates that they book the holiday home are between May 5th 2018 and May 12th 2018, which means the movie is set in 2018. But later in the movie, when Cassie finds the video of Bryan with the two women on his phone, the date is listed as "Sunday, May 7", and May 7th 2018 was a Monday, not a Sunday. (00:01:05 - 01:10:55)
Factual error: An ambulance is shown. This movie is supposed to take place in a latin country. But the ambulance says "Ambulance" in English, and worse, it also says "Riverside County." Also, the red cross emblems on the attendants' backs say "Comite" in Spanish, "International" in English, and "Geneve" in French. (00:28:55)
Factual error: Detective Summerville tells Sean that his wife got a rental Kia from Budget paying in cash. But Budget does not allow the initial cost to be paid in cash; the payment must come from credit or debit card, cash can be used only as the last payment when you return the car. (00:37:30)
Factual error: When Lukas takes Sarah to school (on Friday or only a couple days after taping his laceration), the laceration is much smaller (practically healed) and there are only three strips of tape. A laceration as wide as the one Lukas had would not heal within a couple, few, or even several days. Also, the way Lucas taped his laceration would not yield the same/similar results as sutures (even closure and faster healing with little scar). (00:15:43 - 00:16:31)
Factual error: The shop owner shows him a tape of the Joshua Tree by U2 and says it is the best concert he has seen, but the Joshua Tree wasn't released until 1987.
Factual error: "Polis" is written on two police vans outside the Stockholm bank Taj (Ethan Hawke) is robbing, but police in Sweden are "polismyndigheten" or commonly known as "polisen" (the police). The word "polis" actually means "city." Also, police in Sweden have traditionally used Volvo cars or wagons, not mini vans. (00:13:03)
Factual error: There are no law enforcement agencies referred to as "Mounties" in Alaska, or any elk.
Factual error: The police officer that shows up does two stupid things in a row that real police would never do. When investigating a kidnapping, he calls in what the car was they were looking for. Which he sees. Instead of calling for back up, or even mentioning to dispatch that he found a car that looks like it, after coming from a murder scene at a gas station and following a map left behind to this spot, he approaches the car alone, without calling for back up, or drawing his weapon. Shortly thereafter, he finds the kidnapped boy inside the car, who tells him the man who took him is in the house. The officer then proceeds to go into the house alone to look for a dangerous kidnapper without waiting for backup, even mentioning to the kid that his partner is on the way. (00:32:00 - 00:33:35)