Other mistake: Right at the start, as they're crashing, the computer narrates their rapidly-dropping altitude in feet. But the "altitude" dial we're shown is in metres. Most noticeable as they cross the 3,000 mark, when the computer voice and the height say/show the same number at the same time, despite the different units. 3,000m would be more like 9,000 feet, or 3,000 feet would be more like 1,000m. (00:03:20)
Factual error: A thief has stolen 75 million dollars. He runs out with two large duffel bags. All US bills weigh a single gram. This means that $1,000,000 in $100 bills - the largest bills in circulation - weigh around 10 kilograms, or a little over 22 pounds. $75 million would be 1,650 pounds. No way this could be carried in two duffel bags.
Other mistake: Episodes 4 and 5 of season 1 aired noticeably out of order. In episode 4, "The Nanny," Alex's former Nanny, Rosalba, comes to work at his podcast company, and its name, "Ajana," is mentioned a few times. But episode 5, "The Mother-in-Law," starts with the company unnamed; over the course of the episode, Alex learns of the concept of "ajana," the unknown, from his mother-in-law and chooses it as his company's name.
Plot hole: The FBI is looking for a "very tall" guy who has been identified as such by various witnesses and by their own expert due to the entry angle of a fatal bullet wound - 6'5" at least. They send Elena into a bar near the end of the show to meet the Albanian perp who when he arrives is barely average height.
Character mistake: The firefighters state that the acronym for CPR is ABC for Airway, Breathing, Circulation. This is very outdated as in 2010 the American Heart Association changed the recommendation to CAB for Compressions, Airway, Breathing following evidence that compressions first in CPR saves more lives.
Visible crew/equipment: Right before Anissa and Tavon are attacked by Khalil, the shadow of a camera can be seen on the ground in the bottom right corner of the screen as they approach the path.
Character mistake: Budd is constantly shown buttoning up his jacket when he exits the limousine prior to Julia exiting. As a PPO, SOP is to unbutton to make reaching his firearm easier, not harder! Also, when he buttons, you cannot see the firearm on his belt at all, even though the jacket is quite tight.
Other mistake: The shopkeeper hands Danny a Beretta 92fs/M9 handgun with a detached suppressor. To mount a suppressor to the muzzle end of the handgun the barrel needs to be threaded, and this one isn't. Sometimes barrels are threaded and when no suppressor is attached they are protected by a thread barrel cap to protect the threads from dings and bumps. There is no thread cap here either. (00:22:35)
Factual error: Joseph is given an American military funeral. The coffin, when placed in the ground, is shown with an American flag placed on top of it. Eugene sprinkles some soil over the coffin (with the flag on top of it), however burial flags are always removed prior to the actual burial, folded and then handed to the next of kin, so the soil he sprinkled would not be included in the actual burial. (00:29:10)
Visible crew/equipment: During the strobe lighting at the very end of series three, with Faustus Blackwood seemingly releasing something evil, it is noticed that during the flashes, it is leaving after effects, showing the shape of the equipment that make the strobe lighting. (00:58:00 - 01:00:00)