Other mistake: When they show the comic book and Hiro looks up the artist's address, it is listed as 215 Reed St. 7. The door to the artist's loft says his address is 681. (00:01:10)
Other mistake: Peter rescues Angela from an elevator by flying her straight up the elevator shaft. When we see the shaft, it is completely devoid of any elevator cables.
Other mistake: After Peter falls on the cab, a piece of metal is sticking out of his chest. He pulls himself off it, but when he's on the hood, the piece that was sticking though him isn't there, even though it should be visible.
Other mistake: When Niki looks at the Cadillac's registration, it says the license plate number is "307RTH." When she opens the trunk, you can see the plate and it's "329OCX."
Chosen answer: Because he's an idiot. From the story point of view, they needed the vault to actually be physically open so that the release of the virus would be a credible threat. Unfortunately, this required that Peter conveniently forget that he could simply walk through The Wall and use his telekinesis to tear the door open instead. Peter's increasingly large arsenal of abilities, where he ended up having pretty much any ability required for any situation, led to a situation where it became necessary to either have Peter apparently forget that he had a given power, as with the vault door scene, or become naively trusting, as with his refusal to scan Adam's mind to confirm his good intent. This problem, which simply made Peter look increasingly dumb as the show progressed, may well have been a key factor in the decision to severely reduce his ability during season three.
Tailkinker ★