In Krasnik city, they catch a red train under the Polregio banner to go back to Lublin, but in the next scene, they are already in a blue train operated by PKP Intercity.
At one point in the movie, the characters ride in a Mercedes-Benz taxi, which is initially a W201-based 190, produced from 1982 to 1993. When the taxi arrives, it has magically transformed into a much newer W204 C-Class, produced from 2007 to 2014.
When Benji and David are eating soup outside, the amount of drink in David's glass changes constantly in between shots.
When they are boarding the airplane to Warsaw, Benji and David have a conversation about their seat numbers 24A and 24B which should be on the left side of the aisle, but in actual fact they sit in seats E and F on the right side of the aircraft.
David speaks of Benji taking a train from New York Penn Station to Binghamton, but there are no trains that run between New York and Binghamton.
One morning on the trip, David wakes up and calls his wife in New York. Given that Warsaw is 6 hours ahead of New York, this would be the middle of the night for his wife. The video call does not suggest that this is the case, and nor is it in character for David to do this - he would be more likely to wait until her morning, his afternoon, to call her.
At 20 minutes and 5 seconds to 6 seconds the mic distorts as Benji sits.
There are no direct trains from Warsaw to Krasnik. You have to change in Lublin.