Avodah Zara 70: When are Guards Trusted?

Some brief notes on today's daf:

• cases describe whether wine might be permitted in a number of different contexts
• when a Jew is with a Gentile prostitute, lust will cause him to neglect his guarding duties
• when a Gentile is with a Jewish prostitute, she might be like them and allow them to stop guarding
• if we can see barrels of wine through a crack in the door, we can only guard the barrels we can actually see
• if wine is guarded in a house where the Jew on the second story and the Gentile on the first story and they argue outside and the Gentile returns, the wine is permitted because the Gentile assumes he would be seen if he touched the wine
• A Gentile who has a reason to be near a house where wine is stored and he is there and not afraid, it is forbidden
• If a Gentile is left alone with wine, it is forbidden
• If a Jew and Gentile were drinking together when the Jew was called to pray, the wine is permitted because the Gentile is concerned that the Jew will remember the wine and return for it
• If a Jew and Gentile drink together on a boat and they hear the shofar blast to announce Shabbat and the Jew goes ashore, the wine is permitted because the Gentile thinks the Jew will return, or because he thinks that the Jew won't observe Shabbat, the wine is permitted
• Isar the Convert teaches the rabbis that Gentiles believed that Jews do not observe Shabbat because they would not want to lose profits on Shabbat
•  Rabbi Yitzchak's law: if one found and took a wallet before Shabbat (there was no-one else to carry it), on shabbat he may carry it up to four amos at a time
• If a Gentile hid in the winepress after hearing a lion roar, the wine is permitted - he assumes that Jews are hiding, too, and so he won't touch the wine
• When thieves came to Pumbadita and Neharde'a and opened lots of barrels of wine, Rava permitted the wine because more than half of the population of each city was Jewish and so the thieves are assumed to be Jewish
• If a person goes to a valley and is unsure whether he was in a field with ritual impurity, he is considered to be ritually pure
• If he is not sure whether or not he touched the impurity, he is ritually impure
• Some rabbis assert that Gentile thieves would not touch the wine because they opened the barrels to look for jewels and left the wine untouched
• If a young Gentile woman was found with barrels of wine and foam was in her hand, the wine is permitted, says Rava, because the foam might have come from the outside of a barrel
• when generals came to Neharde'a and Eretz Yisrael and opened many barrels of wine, the barrels are permitted and the rabbis offer a number of possible reasons for this
• A Jewish woman who used to sell wine and gave keys to a Gentile guard, the rabbis agree that she only gave the keys to the Gentile thus she will not touch the wine
• If a chaver, a Torah observant Jew, gives his keys to an ignorant person to guard, what is ritually pure stays ritually pure because there was no permission to touch anything 
• The rabbis discuss the safe ritual status of ritually pure items belonging to a chaser who lives next to an ignoramus, divided by a fence with windows
• In other circumstances, like if the houses were adjacent to each other, items might or might not be ritually pure
• A new Mishna begins, teaching that if an army entered a city in peacetime, it is forbidden to leave barrels of wine open, but closed barrels are permitted.  Further, in wartime, all are permitted because there is not enough time to touch wine