BT BM 81a(39) :הניחא למאן דאמ׳ פשיעה בבעלים פטור אלא למאן דאמ׳ פשיעה בבעלים חייב‏ : that is fine for the one who said "negligence with (pledged) owners is not liable" but what about the one who said "negligence with owners is liable"?
See the entire entry for nīḥā adv. all right, satisfactory