The two failure modes

One is avoidance — saying nothing, agreeing outwardly, and carrying the disagreement privately until it comes out sideways or never comes out at all. The other is the blunt version, where the disagreement arrives with enough force that the other person spends the conversation defending themselves rather than thinking.

Both come from the same belief: that disagreement is inherently a conflict, so the only options are to have one or to duck it. It is not. It is a normal part of working with people who know things you do not, and it can be done in a way that leaves both the point and the relationship intact.