Continuity mistake: When Taffy, (aka, Echo) and her gang of thieves, blow up a wall that leads in to a high security building, huge amounts of debris lands in the hallway that they must walk on. As soon as they start to walk on that hallway, they become unhindered in their destination because there is not as much debris on the floor as we saw in the earlier shot.
Trivia: In Epitaph II: The Return, Alpha asks Tony, "Why would someone do something so horrible to that face?" He was speaking about the tech on Tony's face, but it was also a reference to season 1 when Alpha sliced up Tony's face with a knife.