As long as a Jew supervises an idolater's presence with wine, there's no concern about the wine - even the supervisor's presence is intermittent. Plus, other cases where supervision makes a difference - unless that intermittent checking leaves enough time for the idolater to take the opportunity to handle the wine in a way that would prohibit it. With the notable issue becoming how long the idolater thinks he has before the supervisor returns. Also, how long IS that amount of time anyway? It depends on the material of the wine stopper -- and perhaps the ability to discern the unstoppering of the wine, even from below. Plus, a comment on the talmudic terms for a non-Jew, idolater, pagan, and so on, and the Jewish censorship of these texts.