A disagreement about tone can become a way to avoid discussing what was actually said.

Objecting to how something was said can be sincere, and it can also be a door out of the room. Once the argument moves to tone, the original point stops being examined, and whoever raised it has effectively changed the subject without admitting to it. Tone genuinely matters when it wounds. It becomes a manoeuvre when it arrives just as the content was getting difficult to answer.

When someone objects to your delivery, try answering the substance anyway and returning to the delivery afterwards. And when you find yourself objecting to a tone, check whether you have an answer to what was said.