I asked him if he enjoyed working on the project, and he confided that, though his work was important to him, as a Mormon, he objected to gambling. This was a conflict for him. As there wasn t another project to which he could be assigned, we agreed to not put his name in the credits. This was sufficient, in this case, to ease his mind and he then worked much more effectively on the project. Resolve conflict through open communication.
Conflict is usually a symptom of miscommunication, or lack of communication.
It could be that the lead programmer is irritated with a design decision that was made, for example, and as he is especially tired near the end of the project, he is not holding his feelings back. It is important to get to the root of the conflict quickly, without getting sucked into the conflict itself, so that matters do not escalate. You, as the Producer, need to be that pillar of strength during these times and find creative ways to resolve conflict. This often requires some psychology on your part, recognizing the human element. Get into the heads of those in conflict.