why shouldn't the owner of the camel be responsible for damages in causing the fire outside from chankuah candles. he knew that everyone was lighting outside so he should have been more careful with his camel and since he wasn't why shouldn't he be held liable.
Sholom Rav,
Your question is the very reason that Rebbi Yehudah in the Mishnah exempts the shopkeeper (as quoted here).
The Rabbanan, on the other hand, hold that although it is a Mitzvah to place the Ner Chanukah outside, this does not absolve one from the responsibility of looking after one's fire. In other words, the onus to guard the fire against damages lies with the shopkeeper and not with the people who pass by with their camels.
We learned a similar concept earlier on Daf 6a where the Beraisa permits emptying one's gutters on to the street in the winter, but renders one Chayav for any ensuing damages.
Be'Virchas Kol Tuv
Eliezer Chrysler.