Iron Forged in Fire: Part One - S1-E1
Continuity mistake: As Tony is attempting to stop the train, the door he is pushing on gives out - he flies through the first car of the train and smashes into the next door. As he is getting up, you see the window of the door is a perfect square. Then the angle changes from outside and suddenly the window design changes, having an additional shape extending from the bottom right corner. (00:19:55)