Musannaf Ibn Abi Shayba 18:911

Abu Bakr narrated to us, he said: Abbad bin al-Awwam narrated to us, from Hajjaj, from Qatadah, from Ka'b bin Suwar: That a man was on a donkey, and a man on a camel met him in a narrow alley. The donkey shied away, and the man was thrown off and sustained an injury. Ka'b bin Suwar did not hold the owner of the camel liable for anything.