When Juliet Higgins (Perdita Weeks) says that she can hack into the security system, she says "unfortunately we're not going to have visual, only audio", and Thomas Magnum (Jay Hernandez) shrugs, replying "Better than nothing." Yet when she gets access to the security system, they instead have video but not audio.
When Juliet Higgins (Perdita Weeks) is waiting for the elevator with the Kalashnikov, the stock is folded. In the next shot, the stock is unfolded, and she has the rifle at her shoulder, but in the immediately subsequent shot, from the original angle, the stock is again folded and the rifle is held at her hip.
When Katsumoto (Tim Kang) is discussing the situation with the SWAT leader and Rick, a bead of sweat on his right cheek keeps appearing and disappearing.
Trees are visible out of the office windows. This shouldn't be so if they are actually on the tenth floor.
Magnum mispronounces "Kalashnikov" (gun) as "ka-LISH-kanov".
When Juliet says she is making a defensive weapon, she says "I believe you Yanks call it a shiv". TC then tells her that "No, it's a shank". In fact "shiv" is the British term for such a weapon.