There is an apparent contradiction in the Tur ch. 390 and ch. 412. In the case of one who is carrying a barrel and it falls and is broken that if the path was at an incline, he is not obligated in damages, but if it is level he is. But in a case of just regular people walking and carrying some bundle that is dropped and causes damage to the person in back, there the law is like R Judah that tripping is considered to be an accident i.e., an unavoidable accident, and he is not liable. there is no difference if it was path was at an incline or level. Rav Shach [law of renting ch. 3 law 2] suggests that there is a higher degree of responsibility if one is hired to carry some bundle as opposed to just carrying one’s own bundle. But the Ramban brings that the law man is always liable to cause damage seems to not correlate to this. He says that the only time we do not say "a man is liable always" is when it is a case of a person that is involved in his own work, (that is a person that is hired to work on some object). Then we say that if an accident occurs, he is not liable. But in this way of thinking there should be no liability even in a case of accident, and that is openly not like what we are saying in Bava Kama page 29 that tripping is an accident and if there is also abandoning the object then one is not obligated at all. [later I saw the ramban himself answers this in two way on bava kama pg. 29 and so far i only saw his first answer] ___________________________________________________________________________________________________ There is an apparent contradiction in the טור. In the case of one who is hired to carry a barrel, and it falls and is broken, that if the path was at an incline, he is not obligated in damages, but if it is level he is. But in a case of just regular people walking and carrying some bundle that is dropped and causes damage to the person in back, there the law is like ר' יהודה that tripping is considered to be an accident i.e., an unavoidable accident, and he is not liable. There is no difference if it was path was at an inline or level. רב שך suggests that there is a higher degree of responsibility if one is hired to carry some bundle as opposed to just carrying one’s own bundle. But the רמב''ן brings that the law man is all ways liable to cause damage seem to not correlate to this. he says that the only time we do not say a man is liable always is when it is a case of a person that is involved in his own work. That is a person that is hired to work on some object Then we say that if an accident occurs, he is not liable. But in this way of thinking there should be no liability even in a case of accident. and that is openly not like what we are saying in בבא קמא page כ''ט that tripping is an accident, and if there is also abandoning the object, then one is not obligated at all.