I don’t think it’s ad hominem if it’s all completely true, and relevant to the subject at hand. “Consider the source” is different from, “dismiss this, because

I don’t think it’s ad hominem if it’s all completely true, and relevant to the subject at hand. “Consider the source” is different from, “dismiss this, because of the source.” It’s an article that makes a good point, but it’s also good to realize that the author is not reliable, so it would pay to do further research, check claims made, and quotes cited.