Shiur Supplement - Daf 95a-b
A. Itmar peshiya be-ba'alim... be-hedya hu de-mikhtav [lines 36-42] We have seen in the gemara that all four shomrim, including a shomer chinam, are responsible for peshiya (negligence). Furthermore, under the circumstance of ba'alav imo, there is a blanket exemption from payment if the animal is stolen, lost or suffers accidental damages or death. What is the din if the shomer was negligent under the circumstance of ba'alav imo?
The gemara [line 36] records an argument between R. Acha and Ravina regarding this very issue: According to one of the Amora'im, the shomer is obligated to pay - just as in the case of EIN ba'alav imo. According to the second opinion, however, the shomer is exempt from payment (just as he would be had the animal been stolen, for example).
In order to understand the continuation of the gemara, keep in mind that the laws of shomrim, as written in the Torah, are divided into three sections. We have already concluded that the FIRST section deals with the laws of a shomer CHINAM; the SECOND with a shomer SAKHAR and the THIRD with a SHO'EL. The halakha of ba'alav imo is mentioned in the THIRD section ONLY and the halakha of peshiya is mentioned in the FIRST section ONLY. Accordingly, the debate between R. Acha and Ravina revolves around the question whether or not we can apply the law mentioned in a passuk to the PRECEDING section only - mikra nidrash le-fanav -(ie. Shomer SAKHAR) or even to the section preceding that - LIFNEI fanav (ie. Shomer CHINAM).
If the halakha of ba'alav imo does not apply to a shomer chinam, from whom the liability of the other shomrim for peshiya is learnt, then we cannot apply the exemption of ba'alav imo AT ALL to peshiya. The converse also holds true: If a shomer CHINAM is exonerated from liability in the case of peshiya be-ba'alim, then this exemption applies to the other shomrim as well.
B Tosafot s.v. Itmar According to R. Chananel we rule that a shomer is exempt from payment in the case of peshiya be-ba'alim. This is in keeping with the principle that whenever there is an argument between R. Acha and Ravina, we decide according to the lenient opinion. This is somewhat problematic as ruling that the exemption DOES apply may be lenient in favour of the SHOMER, but it is not at all lenient when viewed from the perspective of the OWNER. However, the Tosafot explain that since the shomer is the one who is in possession of the proposed payment, it is considered a leniency to exempt him from payment.
C. Tenan ha-sho'el para... [line 43] The gemara now attempts to resolve the dispute between R. Acha and Ravina based on a close reading of Tana'itic sources. This continues on daf 95b.
D. Amar R. Hamnuna... akula milta mashma [lines 14-18] According to R. Hamnuna the exemption of ba'alav imo does not apply unless the owner is working with the animal at the time of the accident. This is in addition to having been contracted at the time the animal was transferred to the shomer.