Continuity mistake: During the early part of the movie, the left rear door of Doc's car is dented. For the rest of the movie, the dent is gone.
Character mistake: At the end of the movie, when Jaggu is listening to the sounds recorded by PK, the audio contains the question which she asked, "Tumhare planet pe sab aise hi hote, bade kan wale?" but does not contain the answer which PK gave, even though he was sitting right there. This seems to suggest that PK did not exist in the real world.
Continuity mistake: During the "Perfect Puppy" silly song, Bob places a newspaper he had been reading on the couch beside him when Larry starts singing. When Bob shows Larry the picture of the dalmatian, the newspaper has vanished. When the shot cuts back to Bob, the newspaper has returned. (00:16:55)
Factual error: While Evans and Eve are still in Grand Central they overhear an announcement which states "According to Port Authority policy This station will be closing for the evening." Grand Central is not part of the NY/NJ Port Authority. Also Grand Central is a terminal, not a station, as trains do not pass through Grand Central, they enter and turn around.
Factual error: In the opening heist, the gang of thieves wants to steal "The Medal of Zeus." A plate at the museum explains that in Ancient Greece, Olympic champions were awarded olive wreaths, up to the 88th Olympics in 424 BC, when a golden medal was given to the victor for the first time. This last bit about gold medals is just made up by the movie. But it also gets the timeline wrong; the 88th Olympics were in 428 BC. 424 BC is when the 89th games took place. (00:03:30)
Factual error: The "Italian" police wear obvious fake uniforms, they're US style.
Continuity mistake: When Dex sees "his" son for the first time, the kid in close-ups is playing with the toy that dangles from above, and there's a toy football by him. In the wider angles none of the above is happening. (00:38:40)
Continuity mistake: While father and son are eating beignets, the passers-by behind them are not continuous between shots.
Factual error: Just like in the previous movie, Herzog is referred to as "colonel", in particular in the WWII museum where Martin reads about his history. But both in the museum's picture of him, and throughout the movie, Herzog is wearing the uniform of a SS Standartenführer. To hold a title of Oberst (colonel), he would have been a member of the Wehrmacht, regular army, not SS.
Continuity mistake: When the crocodile catches the man he bites his right foot off. 5 seconds later as he falls into the water his foot is back. (01:21:05)
Revealing mistake: During the opening, one of the shots showing infographics about the stolen diamond lingers long enough to allow the viewer to spot the most obvious kind of filler text - literally the "Lorem Ipsum."
Continuity mistake: When the young girl is on the beach removing her socks, she takes three socks off.
Suggested correction: Jess is wearing yellow socks with polka dots, and yellow wellies. There are three shots in which we see Jess removing or tossing her two yellow polka dot socks, and one of her yellow wellies.
Factual error: When the guy is talking to him on the phone and the Russian smashes it on the floor, the phone smashes and the battery comes out but the guy other end can still hear him. (01:04:00)
Other mistake: During the driving scene in the woods with the Bronco, at least two shots are reused twice.