Amud 112a

Rabi Akivoh commanded his son Rabi Yehoshuah - צוה רבי עקיבא את רבי יהושע בנו

Summary:
The רשב"ם maintains that ר' יהושע בן קרחה was the son of ר"ע, however תוספות maintains that ריב"ק was not the son of ר"ע.

A mistake, once it enters, it enters - שבשתא דעל על

Summary:
A mistake in learning can be corrected as one grows older, but not a mistake based on an unedited manuscript.