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.
Plot hole: When Scola and Nina enter the suspect's apartment and begin the search, Nina, before she enters one of the rooms says to Scola " come in here you should see this" indicating that she was aware of something important in a room that she had not yet been in.