In this argument, the author asserts that the Woven baskets were not uniquely produced by Palean due to a recent discovery that a so-called Palean basket was found in Lithos. We may partly agree the author's opinion, however, without some critical evidences cannot we accept the argument.
Firstly, the author fails to provide the information of the depth and width of the river in prehistoric era. It is true that the river is currently too wide and deep to cross without a boat, we cannot make sure that the river then was in the same condition. Maybe the Brim River was quite narrow and shallow, which made it easy for people to cross. So unless the author could render some verified evidence showing that the river then is a barricade for people to cross, we could not embrace the argument.
Granted that the river in prehistoric era was considerably broad and deep, we still need to ensure that there were not any other approaches to cross the river. The author fails to rule out the possibility that people could get to the other side of the river through a bridge. Obviously the author should provide us some evidences to support his idea that a boat was indispensable for people to cross the river.
Assuming that residents were not able to cross the river without boats, the author does not rule out the possibility that people then indeed possessed boats. Even though there are no Palean boats found so far, we are not sure whether some boats used to exist. Granted that people then did not own any boats, there is possibility that the baskets found were brought by other people who possessed boats. Those people coming from other places might transport the baskets from Palean to Lithos in trade. So the author need to present concrete evidences to persuade that the basket could not be carried from Palean to Lithos by residents or aliens.
To conclude, the author hastily draw the conclusion that Woven baskets were not exclusively manufactured by Palean people without rendering the essential evidences listed above. To make the argument justifiable, the author should rule out the possibilities that the baskets might be shipped by other people and the residents there never had the ability to build a boat. Besides, the author ought to ensure that the river then was in the same condition as today.