Linnea looks back at the Slytherin and says "If you can't apparate, then run, jump out of a window or something. Just because you can use a charm doesn't mean you should. Until it is known how a charm would affect something like that, it is unwise to try when it matters most. Even the muggles who deal with bombs don't make fast and unexpected moves, they're very careful because some bombs are more sensitive than others."