Should I just go and basically say that this person did a bad job? No, because it’s not true. This person was operating under constraints you don’t understand

Should I just go and basically say that this person did a bad job? No, because it’s not true. This person was operating under constraints you don’t understand with incomplete and constantly changing requirements. You would not have done better in that situation. Other professionals do not stab each other in the back either. You will never hear doctors or lawyers do it. If you have a beef with this person keep it behind closed doors.