ad hom in response to a post to someone else. Not a response to ad homs. An initiation of an ad hom approach in that thread.
And note: this is the regular habit of the person who claims to know the way to peace and harmony. Enter a philosophy forum, despite being someone who does not do evidence or justification, who is not there to justify claims to the people he interacts with, but is there to justify his claims about the people in the forum to future generations.