And if you will say, the people of Hutzal do this; their mindset is nullified by all the other people - ואם תמצא לומר אנשי הוצל עושין כן בטלה דעתן אצל כל אדם
Summary:
By an unusual custom, we say בטלה דעתו even by a locale; by a viable custom, if it is done by an individual we say בטלה דעתו, but not if it is a community.
Rabi Yehudoh says, also the note recipients - רבי יהודה אומר אף מקבלי פיתקין
Summary:
The issue of מקבלי פיתקין is that their purses swing back and forth, therefore ר"י is מחייב, however the ת"ק does not consider it similar enough.
It is broken; The one who taught this, etc. - תברא מי ששנה זו כולי
Summary:
It would have been a greater novelty had the two תנאים stated their rulings in the opposite case. They did not because they were not aware of any difference.