Continuity mistake: When Portnow meets with Bishop at the church, in the first closeup of Bishop's crossword puzzle the word "MUD" is the second word across at the top, and at the center of the puzzle the 4-letter word "GEAR" is written in the 5-letter answer - with the fist space left empty. However, in the next closeup of the puzzle, now the word "ETA" is the second word at the top and "MUD" is the third, and the word "GEARS" has the "S" added, with the letter "G" started properly in the first space of the answer.
Deliberate mistake: In the scene where the group finds out that Jasper has betrayed them and then Bishop uses the flash-bang, the group splits up, and Iris and Capra get into an SUV. Very shortly later, when it goes out of control and crashes, you can see a stunt driver in the SUV wearing blue elbow pads and holding onto the roof, before the SUV hits the ground. (Slo-mo may be necessary.)
Other mistake: During the film Ethan Hawke's pills are talked about between him and his evaluator. When you finally see him open his pill container, it is clear that the pills are actually Ice Breakers breath mints. You can see the trademarked "Flavor Crystals" (the dark blue spots on the white mint).