2) PROVING THAT ONE IS AN EXPERT SLAUGHTERER
QUESTIONS: The Gemara relates an incident in which a butcher slaughtered an animal and made it a Tereifah. Rebbi Yochanan told him that since he was not paid to slaughter it, he may exempt himself from paying for the animal if brings proof that he was an expert at slaughtering chickens. Rebbi Yochanan's ruling follows the principle mentioned earlier in the Gemara that a person who is not an expert is responsible for damages even if he took no money for slaughtering the animal. Since he knew that he was not an expert and not properly trained to slaughter, he should not have accepted to slaughter the animal in the first place.

There are a number of questions on this Gemara.

(a) Why did the butcher need to bring proof that he was an expert in order to exempt himself from payment? The principle of "ha'Motzi me'Chaveiro Alav ha'Re'ayah" should apply, and he should have been exempt from paying unless the owner of the animal could prove that he was not an expert. (RA'AVAD; see also KOVETZ SHI'URIM, and BEIS HA'LEVI 2:4:4 and 3:20:2.)

(b) Another reason why the butcher should not have been required to prove that he was an expert is the principle (Chulin 3b) that if an animal is found slaughtered, one may assume that the slaughterer was an expert because "Rov Metzuyin Etzel Shechitah Mumchin Hen" -- most people who are involved in Shechitah are experts. (SHACH YD 1:4)

ANSWERS:
(a) As explained earlier (see previous Insight), the butcher is considered a Shomer Chinam when he receives no payment for his services. The reason he is exempt (according to the Rabanan who argue with Rebbi Meir) when he makes the animal a Tereifah is that the damage is considered damage caused by an Ones, rather than by a Peshi'ah, since it is unusual for an expert to ruin the Shechitah (see RASHI DH Uman Patur). In order to exempt himself from payment, every Shomer Chinam is required to prove that he was not Poshe'a, negligent, when he watched the object, either by making an oath or by bringing testimony of witnesses. (Similarly, if a Shomer Sachar seeks to exempt himself from payment by claiming that the object deposited with him was damaged b'Ones, he must either make an oath or bring witnesses to prove that it was damaged b'Ones.) Since the butcher, who is a Shomer, wanted to exempt himself by claiming that the animal was killed b'Ones and not through Peshi'ah, Rebbi Yochanan required that he prove that there indeed was an Ones by making an oath or by bringing testimony that he was an expert.

This principle -- that a Shomer is exempt only after he proves that an Ones occurred by making an oath or by providing testimony -- does not contradict the rule of "ha'Motzi me'Chaveiro Alav ha'Re'ayah," since this was part of the understood agreement of the Shomer when he accepted responsibility for the object of another person.

The question that remains is why the butcher needed to prove, with the testimony of witnesses, that he was an expert, and he could not exempt himself from paying by making an oath that he was not Poshe'a, like any other Shomer Chinam. The RA'AVAD answers this question by citing the Gemara in Bava Metzia (83a). The Gemara there teaches that if the object deposited with the Shomer was damaged in a manner in which there are likely to have been witnesses who can testify whether it was damaged as a result of an Ones or not, the oath of a Shomer does not exempt him. He must bring witnesses to prove that he was not Poshe'a. Similarly, it is usually common knowledge whether the butcher is an expert or not. Since it is possible for him to bring testimony to prove that he is an expert, it does not suffice to make an oath.

(b) The Shach's answer for why the logic of "Rov Metzuyin Etzel Shechitah Mumchin Hen" does not apply here is unclear. According to the PRI MEGADIM, the Shach means that when a Shochet ruins the Shechitah, the Rov is no longer reliable to state that the Shochet is an expert. REBBI AKIVA EIGER (on the Shulchan Aruch) asks that according to this approach, if it is known that a Shochet once made an animal a Tereifah, the Rov should not be reliable any more to establish that he is a capable Shochet!

The BEIS HA'LEVI (2:4:4) answers that "Rov Metzuyin" is no more than an assumption that if one would ask the Shochet (who slaughtered the animal) whether he is a trustworthy, capable Shochet, he would say that he is. It simply shows that he considers himself a good Shochet. (He bases this on the words of the Rambam and the Re'ah in Bedek ha'Bayis.) Hence, that Rov certainly cannot be used to exempt the Shochet from paying since his own testimony about himself cannot exempt him.

If it is true that the butcher must bring proof that he is an expert because of the Halachos of Shomrim, it could be that the Rov is not a sufficient proof because of the principle that "Ein Holchin b'Mamon Achar ha'Rov." Therefore, the butcher must bring testimony of witnesses to prove that he is an expert (in order to exempt himself from liability).

Another possible answer may be derived from the words of the NIMUKEI YOSEF. He explains that when the Gemara says, "If you are a Mumcheh for [slaughtering] chickens," the word "Mumcheh" means an "Uman Mumcheh," an expert professional. "Rov Metzuyin" might prove that the butcher is a regular Mumcheh, but not a particularly expert Mumcheh, and thus a Hedyot -- an amateur -- also falls into the category of a regular Mumcheh. Therefore, it is not sufficient to exempt him from paying unless he proves that he is an Uman Mumcheh.