Weissman may have prosecuted the case. Comey was deputy attorney general at the time. In fact, I think he is the one that announced the indictment.
My recollection is that Comey was heavily involved in the decision to go after Arthur Andersen as a company, rather than the actual employees who were involved that were criminally negligent with regard to their professional responsibilities.
He may have been. Read the link I sent you. Weissmann’s role is there in black and white (with hyperlinks in the story to other facets).