The Gemara explains that the argument between Rabbi Yehuda and the Hakhamim in the Mishna (10b) is a disagreement as to whether it is appropriate to search for hametz when the prohibition has already begun. Rabbi Yehuda believes that searching can only be done prior to the time when hametz is prohibited, lest someone find hametz and eat it. The Hakhamim rule that if someone has not searched his property before Pesah, he can even do so on Pesah itself.
A similar argument between Rabbi Yehuda and Rabbi Meir is brought by the Gemara, with regard to the rule of hadash – grain from the new harvest that cannot be eaten until after the Omer sacrifice is brought on the second day of Pesah. However, both seem to take positions contrary to what they say regarding hametz (the assumption is that Rabbi Meir is one of the sages who are the Hakhamim of our Mishna).
According to the Mishna in Menahot, by the time the Omer sacrifice was brought, the markets of Jerusalem were filled with flour and other products made from the new grain. Clearly people were involved in harvesting and preparing these products before they could be eaten. Rabbi Meir says that this was done against the wishes of the Sages; Rabbi Yehuda said no objection was raised. In this case, it is Rabbi Meir who seems to fear that handling forbidden food will lead someone to eat it, something that does not seem to concern Rabbi Yehuda.
Rava explains that there is no contradiction between the positions of Rabbi Meir in the two cases, because the person is searching for hametz in order to destroy it, so there is no fear that he will eat it, as opposed to hadash, which will become permitted in a short time, and people may not take the prohibition very seriously.
Abaye explains the apparent contradiction in Rabbi Yehuda’s positions by pointing out that hadash has been forbidden from the moment it was harvested until today, so people are careful not to eat it. Hametz, on the other hand, is something that people eat all year round and therefore will not know to avoid.
Rav Ashi proposes another way of distinguishing between hametz and hadash, but the Gemara rejects his suggestion out of hand with the expression beduta hee or, according to some readings, baruta hee. These expressions appear in the Gemara a number of times, usually in the context of rejecting a suggestion made by one of the later amora’im like Rav Ashi. The term beduta is a very strong one, meaning erroneous or unfounded, and it is understood to mean that the Gemara is insisting that Rav Ashi could not possibly have made such a suggestion, and it must have been attributed to him in error. The term baruta means external, meaning that the statement cannot be accepted and must remain outside the walls of the beit midrash.