I agree with the distinction between disciplines and the Wikipedia definitions are very easy to understand. In my experience, there is some overlap (some IDs are very good engineers, some DEs are very good designers). And I am concerned with how neatly (crudely?) the author identifies the most basic fault of the designer, engineer, and the client. I feel this greatly underestimates anyone in each of these three roles.
There are numerous workflow models the DE, ID, and Client can utilize to bring a new product to market. When the author definitively states "My job is to design a working product and send that to an industrial designer to dress it up." really understates (or undercuts) the fullness of a successful collaboration between these two disciplines and their responsibility to the client.
The methods that develop and deliver the best products are those methods where the engineer and designer work in tandem with the client to address the elements of function, user interaction, feature set, market placement, packaging and production, material, aesthetics, etc. This is by no means a complete list. The point is, when successfully communicating and employing collaborative methods the team is able to minimize 'redesigning of parts at the client's expense', clarify the functional differences of the designer or the engineer, and the reduce the hidden costs and surprises from the client's point of view.
Just my two cents...