Definition: The manner in which an argument (or arguer) is presented is felt to affect the truth of the conclusion
The manner in which an argument (or arguer) is presented is taken to affect the likelihood that the conclusion is true. While it is true that the manner in which an argument is presented will affect whether people believe that its conclusion is true, nonetheless, the truth of the conclusion does not depend on the manner in which the argument is presented.
In order to show that this fallacy is being committed, show that the style in this case does not affect the truth or falsity of the conclusion. (Davis: 61)