Bava Kamma 107 - Shabbat February 17, 8 Adar 1

Study Guide Bava Kamma 107 Rabbi Chiya bar Abba's third statement in the name of Rabbi Yochanan is that one in not liable to payment for claiming an item one is watching is stolen unless there is a partial confession and partial denial (modeh b'miktzat). This is a subject of debate between him and Rabbi Chiya bar Yosef who holds that modeh b'miktzat is not relevant in this type of case - only in a loan. What is the logic behind his distinction? There is a three-way argument regarding the relationship between shlichut yad (where the shomer used the item he was watching) and the case where the shomer claims the item was stolen. If the shomer used the item and then claimed it was stolen, is he/she obligated in the double payment or do we say that first he/she was obligated for shlichut yad in which case he/she acquires the object and is now responsible even for accidental damage or do we say that the obligation for claiming it was stolen is only in a case where there is shlichut yad? Or possibly both are options.