Bechorot 18: When Twins Arrive Simultaneously

In Mishna 17b, we learn that the tana'im disagree about bechorim twins whose heads present at the same time.  Rabbi Yosei HaGelili rules that both are considered to be firstborn and are given to the priest.  The Sagesays that this is only one can be firstborn.  Rabbi Tarfon rules that the priest can chose the better animal.  Rabbi Akiva says that me-shamnin beneihem, we compromise between them.

Today's Gemara speaks to Rabbi Tarfor's reasons that we can assume that the stronger one came out first.  Rabbi Akiva's ruling is unclear.  Rabbi Chana bar Abba quote Rabbi Yochanan teaching that Rabbi Akiva meant that the kohen gets the leaner of the two two animals. which can't be true if there is compromise. Perhaps Rabbi Akiva meant that they must divide the value of the animals equally.  Rabbi Yochanan responded: What you were eating dates in Babylonia, we explained Rabbi Akiva's statement from the end of the Mishna.

Rashi understands this as an expression of scorn - while you were living in luxury, here in Israel we already explained this passage.  Tosafot note that the dates stated by by Rabbi Yochanan were inferior dates; not at all luxurious.  They argue that Rabbi Yochanan was says that  'you would have been better off coming to study with me in Israel instead of eating 'bad dates' in Babylonia.
Steinsaltz teaches that Rabbi Mordecai Shimon Rubinsky says that the dates were unripe and that Rabbi Yochanan wasn't suggesting that Rabbi Chiyyah bar Abba reached an inaccurate conclusion.  He would have waited patiently until the end of the Mishna where it would be have been clear that he misunderstood Rabbi Akiva's position.