Barney sneaks into Townsend's apartment to change Townsend's time on the watch. He changes it from 4:35 to 4:05, meaning the real time is now 4:35, the time Townsend will think as real is 4:05. However in the very next scene we see Vincent (Miklos' lieutenant) at the airport with the clock behind him, clock displaying 4:15. If this action really takes place after Barney's presence in the apartment, it should show a time after 4:35, not before.
As Miklos is accusing Townsend of being a traitor, he asks to see his watch. As he compares it to his own watch, he is wearing a watch with a leather band. But in the next shot, Miklos' watch now has a metal band.
When Barney and Willie pose as repairmen to fix a gas leak, they are wearing filter masks. Filter masks would provide no protection from a natural gas leak.
The floor from Townsend's apartment to the elevator is continuous, revealing that it is not a real elevator as there would be no way for it to move.
When Cinnamon is playing as Sandra, she calls Walter Townsend's apartment to so that Miklos will go break into her apartment to find out more info about her and her connection to Townsend. On the table by her phone is a lump of clay, which apparently is the same clay Miklos will later take out of his pocket to make impressions of her keys.
Barney is using acid from a syringe to get access to the bottom of the statue. However, he is not wearing any type of protection, such as eye protection, face shield, gloves.