We are told bdsm relationships are what the partners want them to be. There is no bdsm rulebook. It follows therefore that the Dom who felt disagreement is disrespectful can only speak for himself and not for bdsm relationships as a whole.

Since there is no bdsm rulebook we can only seek guidance for an answer to this qustion in other situations where there is power authoritu differential eg military, historical slavery, customer service industries eg hotels. There are cases where the rule is, dont speak or venture opinion unless asked to do so. In that scenario expressing disagreement without being asked is not allowed. In other cases it is a case of how the disagreement is phrased. We can look at the stereotype butler for how disagreement or correction is done eg Perhaps his lordship has not taken into account how tired I am having been working all day.

Power is about who makes the final decision. It does not mean there can be no inputs into the decision making process.