By his own logic, he probably can't, he said he used the heuristic to decide whether the article was worth spending attention on, which would result in a no, an

By his own logic, he probably can't, he said he used the heuristic to decide whether the article was worth spending attention on, which would result in a no, and thus the conclusion that he hadn't read it. Not having done so, he can't address the argument. So it is ad hominem, but maybe by accident if you want to be very generous.