Disqualifying a Dayan for Having His Lost Item Returned

(based on Chelkat Yaakov, Choshen Mishpat 1)

Case: On the way in to a beit din hearing, one of the litigants found and returned the lost object of one of the dayanim. Does that disqualify the dayan from adjudicating in his case?

Ruling: The querying rabbi cited the Tumim (34:18), who compares the disqualification due to a concern of "bribery" to the case of what Reuven is allowed to "receive" from Shimon when Reuven is forbidden due to an oath to receive benefit from Shimon. The Tumim says that in cases in which it is not halachically considered receiving benefit regarding the severe laws of oaths even though one is involved in putting the other in a more advantageous position, it is certainly permitted regarding the less severe laws of concern of indirect bribery. Shimon is allowed to return Reuven’s lost object despite the oath that Reuven may not benefit from Shimon (Nedarim 33a). The logic is that the returner of a lost object is not doing a favor for the owner but is simply following Hashem’s mitzva. Thus one can argue that if a litigant returns a lost object to the judge, the judge is not disqualified.
However, it seems simple to me that it is forbidden for the dayan to act as a judge in this case, although it is possible that this is just as a stringency. This contention is based on a comparison to a case in the gemara (Ketubot 105b). It tells of a dayan who disqualified himself because his sharecropper made his payment a day earlier than required when coming before the dayan/field owner for a hearing even though he was only receiving that which he deserved. Similarly, the gemara tells of Shmuel disqualifying himself because a litigant outstretched his hand to him before a hearing. One could have said that the litigant was not doing a favor to Shmuel but observing the mitzva to show respect to a talmid chacham (see Yoreh Deah 244), and yet Shmuel recused himself. There is a machloket whether these disqualifications were by law or based on chumra.
It seems that the Tumim’s leniency applies only to "late bribery," i.e., benefits that a litigant provides for a dayan after a ruling has already been handed down (see Sanhedrin 27b with Rosh). Just as there is a Rabbinic prohibition against taking voluntary interest even after a loan’s repayment is complete, so too it is forbidden to receive payment from a litigant after the ruling. In that context the Tumim stated his leniency to allow borderline benefits that are not considered benefits in the context of oaths. However, regarding benefits before or during the judicial process, which is a question of a Torah violation and in a setting in which warming of feelings between the two could affect the dayan’s judgment, it does not help that such benefit is permitted concerning oaths. For example, is it possible that a litigant can teach a dayan’s children or pay off his loans (see Nedarim 38)! Such matters are inconceivable when we consider some of the minute things that the gemara says disqualify a dayan. Although the language of the Tumim seems to indicate that he is referring to benefits provided before a ruling, there are indications of textual problems in this Tumim. In any case, it is impossible to be lenient in such a case.