Continuity mistake: Agent Keen breaks the train window and dives through the broken glass and cuts her face in two places as she pursues the young man. Her two cuts alternate throughout the following scenes on the train from dripping blood to barely scratches. That evening at home with her husband her face is practically clear and at Reddington's home later that evening her skin is perfect.
Continuity mistake: The BMW 5 Series equipped with the dirty bomb you see in the beginning of the show is one of the 'F10' type. The car that actually explodes is another car. Possibly an elder 5 Series 'E34', but not an 'F10'. Later in the episode you see the F10 again, but when the FBI agent starts the BMW, the interior of an 'E60' BMW 5 Series is shown.