Eruvin 80: Behind the Husband's Back

First, mention of eruv tavshilin. Then: A disagreement between Rav and Shmuel whether one needs to take possession of the eruv. And then that comes to a head in a real case, in which a mother-in-law prepared food for the daughter-in-law's eruv, but the daughter-in-law was not involved. The case is then explored by many, thinking to be more leniently, and, at the end of the day, the conclusion appears to have been unanimous. Which leaves us with some questions, as it happens. Also: A non-Jewish superintendent in R. Zeira's neighborhood declined to rent out his space for the sake of making an eruv. They decide they should ask his wife, to see if maybe she'll sign on in his place - and the question is whether her authority will work, for this purpose (recognizing that he won't know). The case is then brought a second time, with R. Yehudah bar Oshaya in place of R. Zeira. With the same outcome. Which is confirmed by Shmuel. Which, in turn, contradicts a beraita - how could Shmuel have contradicted the beraita? Indeed, the Gemara has a nice solution in terms of how the cars are different. Though why halakhah about Jews is being applied to a non-Jew is a conundrum.