The משנה in אבות ה:י”ז speaks about the difference between a מחלוקת לשם שמים and a מחלוקת שלא לשם שמים. One of the prevailing interpretations of the מחלוקת לשם שמים, exemplified by הלל and שמאי is that both sides of the dispute actually share a common goal. They are each seeking to reach the common goal of the proper way to understand a סוגיא and thus, the proper way to serve the רבש”ע.
This is – perhaps subtly – on display in this גמרא. The גמרא asks a קושיא on עולא’s opinion cased on a ברייתא. But רבא, in conjunction with רב חייא בר אבין offers an understanding of the ברייתא which evades the קושיא. But wait, who was עולא arguing with? None other than רבא himself. So even while רבא is embroiled in this dispute with עולא over how to understand our משנה, he nevertheless comes to his defense to reject the גמרא’s question.