Ad hominem (to the person) arguments make everything seem personal, or that the person you are talking to is making a statement about you or your personal character, or ability.
As testers we must work to minimise this type of discussion or argument. We almost always have some bad news to deliver…the product doesn’t work, the product can’t go live.
De-personalise reporting, feedback and discussions. Talk in terms of the product, not the developer who wrote it. It’s not always easy but this separation is key to fostering strong relationships, it can also be the foundation to more open and direct conversations later.
Avoiding ad hominem is the foundational element of civil discourse.