I took it as Andrea being close enough that the unsuspecting waiter walking sideways past (and closer to) the blast would be knocked more or less off balance, the flying drink being caused more by his flailing about trying to keep from falling than the blast itself, after all, that might have spilled the drink she managed to scoop out of the air.<br/><br/>And gods yes, Stephen's poor bum must be awfully sore, lucky thing he is with such a gentle and delicate flower...oh, wait, nevermind. (-: