Continuity mistake: Episode 3x13, "A Clear and Present Danger": When Usutu is talking with Matt in Matt's apartment, Usutu's walking stick jumps back and forth from horizontal across his shoulders, to vertical in his hands, and back to his shoulders. (00:23:40)
Factual error: The solar eclipses in the show that affected the characters' powers were referred to several times as "global events". In the episode with the second eclipse it's shown to be visible in locations thousands of kilometers away from each other at the same time. This is simply impossible, since a solar eclipse occurs when the moon passes between the Earth and the sun, casting a moving shadow that can be only about 250 km in diameter (for a total eclipse). The partial eclipse can be viewed in a much wider region, but the eclipse in the show was a total one. It's not a global event, but a local one.
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 ★