Explanation #1: The Rashbam explains that this was Rebbi yehishua ben Korchah, since Rebbi Akiva was bald ...

Source: As the Gemara says in Bechoros (Daf 58.), where ben Azai declared that all the Chachmei Yisrael were before him like the peel of a garlic, with the sole exception of 'this bald man' (i.e. Rebbi Akiva).

Refutation: But it does not correct to say that the Gemara would call him 'ben Korchah' in a derogative way ...

Reason: Since we find that the youths who called out to Elisha (n Melachim 2, 2) "Come up baldy, come up baldy' were punished.

Explanation #2: And ben Azai called Rebbi Akiva by that name by way of jest.

Question: Rava himself in 'Lo Yachpor' (Bava Basra, Daf 21.) that 'An error goes out by itself'?

Answer: That speaks where he learns without a text, in which case he learns carelessly, and understands by himself (that he erred) when he grows up.

Conclusion: Whereas here it is speaking about a Seifer which has not been checked, in which case one relies on the Seifer, and the error remains.