When Carol is in in the elevator with Zosia, the amount of saline in Zosia's drip bag changes repeatedly between shots.
The sign in Spanish says "Prohibido la entrada". That's wrong. It should read "Prohibida la entrada".
Carol injects the truth serum intravenously without pulling back on the plunger to register and confirm the needle is in a vein. No one with experience using drugs intravenously would do this. Injecting drugs in that manner without having the needle in a vein is extremely painful.