We say that by the Tamid shel Shachar since the majority of years the witnesses come after the shir they say the regular shir.So we should say the same thing by the Tamid shel Bein Ha'arbayim, that since the majority of years the witneeses come on the 30th of Elul(as we know from earlier gemorah), then even if they came after mincha the leviim should still say the shir of yom tov. So i don't understand why they were in doubt in what shir to say by the Tamid shel Bein Ha'arbayim??
Donnie Appel, Staten Island, New York
Dear Donnie,
Hello there and thanks for your question. My suggestion is that the witnesses almost always arrived on the thirtieth day after the morning Tamid, before the afternoon Tamid. Thus when this incident occurred that they had not arrived by the afternoon Tamid, it is already not a normal case, thus the statistic of Rav is already not relevant, since in normal years they would have arrived by then.
All the best.
B'hatzlacha.
Y. Landy