Reference for Bava Kamma 37:19
איתיביה דרסה על הכלי ושברתו ונפל השבר על כלי אחר ושברו על הראשון משלם נזק שלם ועל האחרון משלם חצי נזק ותני עלה במה דברים אמורים ברשות הניזק אבל ברה"ר על הראשון פטורה ועל האחרון חייבת מאי לאו התיזה ברשות הרבים והזיקה ברשות הרבים
who is against half damages [in the case of Pebbles]? If you, however, suggest that THE FIRST UTENSIL refers to the utensil broken by a fragment that flew off from the first [broken] utensil, and THE SECOND refers thus to the utensil broken by a fragment that flew off from, the second [broken] utensil, and further assume that according to Symmachus there is a distinction between damage done by direct force and damage done by indirect force [so that in the latter case only half damages will be paid], then [if so] what about the question of R. Ashi: 'Is [damage occasioned by] indirect force, according to Symmachus, subject to the law of direct force or not subject to the law of direct force?' Why is it not evident to him [R. Ashi] that it is not subject to the law applicable to direct force? — R. Ashi undoubtedly explains the Mishnah in accordance with the Rabbis, and the query<span class="x" onmousemove="('comment',' As to the reading of the Mishnaic text. ');"><sup>15</sup></span>