Bava Kamma 100 - Shabbat Rosh Chodesh Adar 1 - February 10, 1 Adar 1

If a money changer mistakenly tells a customer that a coin is valid and causes a loss to the customer, is the money changer responsible for reimbursing for the loss? If the money changer is a real professional, then he/she is exempt but if not, he/she is responsible. However, Rabbi Chiya reimbursed a woman for her loss based on his mistake, even though he was a professional as he decided to go beyond the letter of the law (lifnim meshurat hadin).  There is a case with Rabbi Elazar and Reish Lakish and Reish Lakish explains to Rabbi Elazar that he is relying on his valuation of the coin. If Rabbi Elazar made a mistake, he would need to reimburse Reish Lakish as this would be a case of garmi, and Reish Lakish held by Rabbi Meir who obligates one for garmi-type damages. Where can we find Rabbi Meir's ruling on garmi? Four different sources are suggested - only the last is accepted as the answer. The Mishna discusses three different cases where the dyer did something different from what the customer asked - burned, did a poor job, or colored it the wrong color. What is the halakha in each case?