Mazel Tov! You were Mechaven to the Kashya of Reb Chaim Brisker! This is cited here by the Sukas David #42 DH ube'shem: Reb Chaim Solovetchik answered the Pnei Yehoshua's question by asserting that for Aveidah there is a Mitzvah of Hashavah and a Din of "Until you check out your brother" (Devarim 22:2). The Mishnah in Bava Metzia 28b learns out from here that one has to test him to find out if he is a Ramai. Therefore, argues Reb Chaim, the Bari is not sufficiently strong to prove to the finder that the To'en is the true owner. The finder will say to the claimer "What do I care about your Bari? I have a Mitzvah from the Torah to find out who the owner is, and I do not believe that I should return the article to you, because my obligation is to return it to whoever it is clear to me is the owner, and your Bari does not prove that to me".

[A similar idea is expressed by Reb Shimon Shkopf in Sha'arei Yosher (6:14 DH u'Lefee Zeh). According to the Din of Toras ha'Mishpatim - Monetary Law - since the To'en claims he is a Bari, one should in fact return it to him. However, for a lost article there is an additional Mitzvah of Hashavas Aveidah, which can only be fulfilled through witnesses or Simanim].

However the Sukas David (DH v'Al) explains the Sevara of the Pnei Yehoshua as well. This is in itself the Pnei Yehoshua's question: why did the Torah command that we should demand Simanim from the claimer? Why is the Birur of the Bari not sufficient to extract the article from the finder? If a Bari is capable of extracting property even from someone who has a "Chezkas Mamon", as one sees in our Sugya according to Rav Yehudah and Rav Huna, then Kal v'Chomer the Bari should be capable of extracting it from the finder who does not possess a Chezkas Mamon, because the lost object certainly does not belong to him.

[It seems to me that one can say that the Pnei Yehoshua was not concerned about what Reb Chaim said about the Mitzvah of "Check out your brother". This is because it appears from the Mishnah in Bava Metzia 28b and Rashi DH Chaishinan that this refers to a very low sort of Ramai, someeone who knows the Simanim of somebody else's property and deliberately gives them falsely in order to receive his article.

I want to say there are 3 sorts of people:

(1) A Talmid Chacham (Torah scholar). Bava Metzia end 23b states that one returns the Aveidah to him even without Simanim because it is sufficient for him to vouch that he recognizes the object, because the Talmid Chacham does not lie.

(2) Am ha'Aretz (unlearned). He is suspected of lying so one does not return it to him merely with "Teviyas Ayin" without Simanim (see Tosfos Chulin 96a DH v'Lo).

(3) Ramai (cheat). He is suspected even when he gives Simanim.

I suggest that the Pnei Yehoshua learned that the principal Mitzvah of "Check out your brother" applies to type (3). I think this fits in well with the Mishnah 28b if you look carefully there. For such a person the Pnei Yehushua was certainly not trying to suggest that one should believe his Bari, because if we do not believe when he provides Simanim, we certainly do not believe him with a Bari.

I admit that the above does not fit in so well with the words of the Pnei Yehoshua, but I think one is forced to distinguish between different levels of people concerning the Mitzvah of checking the brother.]

See also Teshuvas Chasam Sofer EH 1:57 DH u'HNLAN'D and EH 2:144 DH u'Ma'alaso and see the Birkas Avraham in our Sugya.

You have a very nice Chabura there! Behatzlachah Rabah!

Dovid Bloom