Sorry puking up my guts, feel free to try to take advantage of it if you wish, if no one takes you up on that I'll take the throw resolve.
For those unsure of what happened, null magic triggered when Drusilia went through the barrier. She briefly weakened it. (due to the nature of what she is) No, this is not license to destroy the barrier by the time she puked it was already back at full strength. (This would be in keeping with the idea of not destroying the magical barrier to prevent power gaming) This is one of the two uses of Null magic she has going for her.
The second thing is Drusilia came into contact with magic and therefore reacted appropriately.