Lucas was a dork. He was a highly intelligent dork. We could sit here reading about his credentials and how awesomely Marty Stuish he was in canon, but that's not important right now. And, in fact, it's really quite boring. The important part was that, although highly intelligent and having a high technical aptitude, he was also a dork who often had to deal with the consequences of his hastiness.
That was why he was magnetically sealed in his own room thanks to a magnetic lock on the door and window gone wrong. Well, not wrong if you asked him, because it worked perfectly. The room was impenetrable unless you were small enough to deal with the room's ventilation. Unfortunately, the part that he hadn't thought about was how to undo it.
He could absolutely, definitely undo it. It could be done. It would be done. Just not right now because he couldn't think of a solution yet. He was pondering another attempt when the phone rang.[OOC: For keds_champion]