Continuity mistake: When Matt Parkman gets thrown out of a window by Niki Sanders, he lands at least a few stories down and has a cut upon his head. The amount of blood on his head differs significantly from shot to shot.
Continuity mistake: When Meredith and Nathan are talking in her trailer, as he says, "I could have been a much better person back then", he has his sunglasses in his hand and places that hand on the table. Cut to a shot from behind him, and his hand is resting on the table with the sunglasses beside it, with no time to put them down and move his hand in between the shots. Also, when Meredith says, "You and me, we were never gonna work out", his hand goes from being on the table to his lap between shots, once again without having had the time to move it. (00:32:10)
Continuity mistake: At the end of ep. 1-14, "Distractions", Meredith calls Nathan to tell him about Claire. In that episode he is holding the phone to his ear, with nothing else in it. In the beginning of this episode, when the same conversation is shown, he is holding a pen in the same hand as the phone. Also, in ep. 14 Meredith said to him, "We haven't spoken in a long time, but... Our daughter just found me". In this episode, she says, "We haven't spoken in a long time, but I just had... Our daughter just found me".
Continuity mistake: In ep. 1-14 "Distractions", when Claire asks Meredith about her father, Meredith answers, "Well, that's complicated. Why don't you let me work on that for next time?" But when the same scene is shown in a flashback in this episode, Meredith says, "Well, that's complicated. He's kind of a big shot".
Continuity mistake: Peter is pushed off the building faced forward, he is falling face forward, yet he manages to land face upwards.
Chosen answer: Hiro's powers are still quite unreliable, and a locked closet door isn't a huge obstacle. Since Hiro knows he needs to rescue Ando, it's probably safer to try and bash the door down than risk teleporting to the wrong place or time.