Bechoros 4:4-5

Bechoros 4:4

If a non-expert examined the firstborn animal and it was slaughtered based on his approval, it must be buried and the non-expert must pay for it from his own pocket. If a non-expert judged a court case and acquitted the guilty or convicted the innocent, or he declared something ritually clean to be unclean or something ritually unclean to be clean, his ruling stands but he must pay for losses that he caused from his own pocket. If an expert makes a mistake in judgment, he is exempt from paying. It once happened that a cow’s womb was removed and Rabbi Tarfon ruled that it should be fed to the dogs (as non-kosher). When the Sages heard of the matter, they ruled the cow kosher. Todos the Doctor said that no cow or sow is exported from Alexandria without having its womb removed to keep it from reproducing (so it’s clearly not a mortal injury). Rabbi Tarfon exclaimed that he would have to sell his donkey (i.e., take a loss) to pay for his erroneous ruling. Rabbi Akiva told Rabbi Tarfon that he’s exempt from paying since he’s an expert and authorized to rule in such matters.

Bechoros 4:5

If a person accepts payment for inspecting firstborn animals, one may not slaughter based upon his examination unless he is an expert like Illa in Yavneh. The Sages allowed Illa to be paid four isar for examining small animals and six isar for examining large animals, whether they were found to be blemished or unblemished.