If
a custodian transferred a deposit to another custodian without
obtaining permission from the owner, then Rav says that it is NOT an
act of negligence, and the the first custodian doesn't' acquire any
additional liability for losses, since he still guarantees the deposit.
Rabbi
Yochanan says that it IS an act of negligence, and that the first
custodian is now liable even for unavoidable accidents, for which he
was not liable before, because the owner can say to the first
custodian, “You are credible to me with an oath, and that second
custodian is not.”
The final law agrees with Rabbi Yochanan.
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